create elegant display of digits and symbols

Question

I want to create a display of the duodecimal digits of \pi for printing on a T shirt. I've made some progress with help from SE: Fonts larger than \Huge?, How to increase the size of first character in a chapter (Drop-Caps).

Here's my MWE

\documentclass[extrafontsizes,48pt]{memoir}

\usepackage{lettrine}

\newcommand{\sirdot}{\smash{\raisebox{.2ex}{$\odot$}}}
\newcommand{\apple}{\smash{$\Delta$}}

\begin{document}

%3:184809493B918664573A6211BB151551A05729290A7809

\noindent
3.184809493\apple 918664573\sirdot 6211\apple\apple 151551\sirdot
05729290\sirdot 7809

\vspace{1in}

\begin{minipage}{4.5in}
\noindent
\lettrine{3.}
1 8 4 8 0 9 4 9 3 \apple{} 9 1 8 6 6 4 5 7 3 \sirdot{}
6 2 1 1 \apple{} \apple{}
1 5 1 5 5 1 \sirdot{}
0 5 7 2 9 2 9 0 \sirdot{} 7 8 0 9 \ldots
\end{minipage}

\end{document}

I'm asking here for answers to questions about the aesthetics.

• Font suggestions?
• Change the interword spacing? (see How to change the interword spacing?)
• Arrange the display in a circle, or running around a circle, perhaps with the 3. in the center?
• Make the dropped cap 3. an image, perhaps with a circle in the background?

(For information about why I want to do this, see duodecimal page number.)

Edit:

I've accepted @Gonzalo Medina's lovely answer below, with the circular display and font \usepackage[fulloldstylenums]{kpfonts} (and a somewhat smaller central 3.). But ambition knows no bounds.

The \sirdot character does not look as if it belongs in the font. Can I have a new character with that essential shape that fits better? Perhaps the 0 with a dot in the center? And, for good measure - the \Delta does seem to belong (the thick and thin elements match nicely). But the top of the character ought to look more like the top of the 4, and the horizontal should probably be thick rather than thin. Something like this (hacked with images and paint):

Edit:

@Gonzalo Medina answered this new question for \sirdotand suggested importing from another font for the \Deltam. The one from the default font in my MWE may be better than the one in the accepted answer. How do I grab that? The answer at Importing a Single Symbol From a Different Font should do the job.

Answer 1

Here's one possibility, using TikZ and its decorations.text library (the digits are used as text for a decoration); I also used the fulloldstylenums option for the kpfonts package:

\documentclass[extrafontsizes,48pt]{memoir}
\usepackage[fulloldstylenums]{kpfonts}
\usepackage{tikz}
\usetikzlibrary{decorations.text}

\newcommand{\sirdot}{\smash{\raisebox{.2ex}{$\odot$}}}
\newcommand{\apple}{\smash{$\Delta$}}

\begin{document}

\noindent\begin{tikzpicture}[
decoration={text along path,
text={184809493{\apple}918664573{\sirdot}6211{\apple\apple}15%
1551{\sirdot}05729290{\sirdot}7809{\ldots}}}
]
\draw [decorate,rotate=-90] (0,0) circle (7.3cm);
\node at (0,0) {3.};
\end{tikzpicture}

\end{document}

Two variations:

\documentclass[extrafontsizes,48pt]{memoir}
\usepackage[fulloldstylenums]{kpfonts}
\usepackage{tikz}
\usetikzlibrary{decorations.text}

\newcommand{\sirdot}{\smash{\scalebox{.8}{$\odot$}}}
\newcommand{\apple}{\smash{\scalebox{.8}{$\Delta$}}}

\begin{document}

\noindent\begin{tikzpicture}[
decoration={text along path,
text={184809493{\apple}918664573{\sirdot}6211{\apple\apple}15%
1551{\sirdot}05729290{\sirdot}7809{\ldots}}}]
\draw [decorate,rotate=-90] (0,0) circle (7.1cm);
\node at (0,0) {\fontsize{200}{12}\selectfont 3.};
\end{tikzpicture}

\noindent\begin{tikzpicture}[
decoration={text along path,
text={184809493{\apple}918664573{\sirdot}6211{\apple\apple}15%
1551{\sirdot}05729290{\sirdot}7809{\ldots}}}]
\draw [decorate,rotate=-90] (0,0) circle (7.1cm);
\node at (0,0) {\fontsize{100}{12}\selectfont$\pi\approx 3.$};
\end{tikzpicture}

\end{document}

Another one (with a little more patience the font size can be better diminished):

\documentclass{memoir}
\usepackage[fulloldstylenums]{kpfonts}
\usepackage{tikz}
\usetikzlibrary{decorations.text}

\newcommand{\sirdot}{\smash{\scalebox{.8}{$\odot$}}}
\newcommand{\apple}{\smash{\scalebox{.8}{$\Delta$}}}

\newcommand\myfont[1]{\fontsize{#1}{12}\selectfont}

\begin{document}

\noindent\begin{tikzpicture}[
decoration={text along path,
text={{\myfont{150}1}{\myfont{130}8}{\myfont{140}4}{\myfont{130}8}{\myfont{120}0}{\myfont{110}9}{\myfont{100}%
4}{\myfont{90}9}{\myfont{80}3}{\myfont{70}\apple9}{\myfont{60}18}{\myfont{50}6645}{\myfont{40}73{\sirdot}62}{\myfont{30}11{\apple\apple}15}%
{\myfont{20}1551{\sirdot}}{\myfont{10}05729290}{\sirdot}7809{\ldots}}}]
\draw [decorate,rotate=-90] (0,0) circle (6.8cm);
\node at (0,0) {\fontsize{200}{12}\selectfont 3.};
\end{tikzpicture}

\end{document}

For the new requirement made in an edit to the original question, you can use \ooalign to superimpose a \cdot over an "O" or over a "0" and get the desired symbol; the following code illustrates two possible definitions and shows a comparison with the original symbol:

\documentclass[extrafontsizes,48pt]{memoir}
\usepackage[fulloldstylenums]{kpfonts}
\usepackage{graphicx}

\newcommand{\sirdot}{\smash{\scalebox{.8}{$\odot$}}}
\newcommand\sirdoti{%
  \mathord{\ooalign{\hss\raisebox{-0.1ex}{$\cdot$}\hss\cr 0}}}
\newcommand\sirdotii{%
  \mathord{\ooalign{\hss$\cdot$\hss\cr\small O}}}

\begin{document}

$\sirdot\qquad\sirdoti\qquad\sirdotii$

\end{document}

For the other character, perhaps one could impost this symbol from another font?