Numero sign with double underline and matching font

Question

I am currently trying to produce a numero sign which adapts to the used font and has a double underline as in the image:

The \textnumero macro from the textcomp package does not have the double underline and does not match my font. Trying to reproduce it based on existing answers like this or this did not lead to the desired result as well.

This is my current code which is closer to the desired result than \textnumero, but still does not match perfectly:

\documentclass{scrartcl}
\usepackage[utf8]{inputenc}

\usepackage{graphicx}

\usepackage{ulem,amssymb}
\newcommand{\Number}[1]{%
    $\mathcal N$\kern-.15em\textsuperscript{\smash{\uuline{\normalfont\itshape \scalebox{.7}{o}}{}}} #1%
}

\usepackage{yfonts}

\begin{document}

\frakfamily

\Number{4}

\end{document}

How can I improve it or which other approach can I take here?

Answer 1

Similar approach with a TABstack. It adapts to fontsize changes.

\documentclass{scrartcl}
\usepackage[utf8]{inputenc}
\usepackage{graphicx}
\usepackage{amssymb}
\usepackage{yfonts}
\usepackage{tabstackengine}
\newcommand\Number{\begingroup\setstackgap{S}{0.08ex}%
  \ensureTABstackMath{\stackinset{r}{-.05em}{c}{}{\tabbedShortunderstack{%
  \scalebox{.7}{$\scriptscriptstyle o$}\\\TABrule\\\TABrule}}{$\mathcal{N}$}}%
  \endgroup}
\begin{document}
\frakfamily

\Number\,4

\Huge\Number\,4
\end{document}

Answer 2

This yields a similar result as in the example, and it adapts well to different font sizes.

\documentclass{article}
\usepackage{amsmath}
\usepackage{pict2e}
\newlength{\fslength}
\newlength{\fthickness}
\DeclareFontFamily{U}{eus}{\skewchar\font'60}
\DeclareFontShape{U}{eus}{m}{n}{%
    <5><6><7><8><9>gen*eusm%
    <10><10.95><12><14.4><17.28><20.74><24.88>eusm10}{}
\DeclareMathAlphabet\EuScript{U}{eus}{m}{n}
\makeatletter
\newcommand{\Number}[1]{%
    \setlength{\fslength}{\f@size pt}%
    \setlength{\fthickness}{.04\fslength}%
    \pdfsave\pdfliteral{1 0 .25 1 0 0 cm}\rlap{$\EuScript{N}$}\pdfrestore%
    \phantom{$\EuScript{N}$}%
    \rule[.16\fslength]{.25\fslength}{\fthickness}\hspace*{-.23\fslength}%
    \rule[.24\fslength]{.25\fslength}{\fthickness}\hspace*{-.30\fslength}%
    \raisebox{.24\fslength}[.4\fslength]{%
        \centering%
        \setlength{\unitlength}{\fslength}%
        \begin{picture}(.3,.3)
            \linethickness{\fthickness}
            \put(.2,.2){\circle{.2}}
        \end{picture}%
    } #1%
}
\makeatother

\begin{document}
{\scriptsize This is \Number{4} for a test.}

{\small This is \Number{4} for a test.}

This is \Number{4} for a test.

{\large This is \Number{4} for a test.}

{\Large This is \Number{4} for a test.}
\end{document}

As it is, this example has to be compiled with pdfLaTeX. If it were to be compiled with XeLaTeX or LuaLaTeX, the lines

\pdfsave\pdfliteral{1 0 .25 1 0 0 cm}\rlap{$\EuScript{N}$}\pdfrestore%
\phantom{$\EuScript{N}$}%

would have to be changed. The N symbol that I used in this example is a slanted version of the N in Euler script font, but I'm not sure how it can be slanted using other compilers. In any case, the above lines could be changed to simply

$\mathcal{N}$\hspace*{-.2\fslength}%

to yield a similar result than in the picture given at the beginning, but with a computer modern \mathcal{N}.

Answer 3

Not as wide as in the example, but quite similar. A Cyrillic “number sign” with a second bar added.

\documentclass{article}
\usepackage{pict2e,picture}
\usepackage[T2A,T1]{fontenc}

\newcommand{\simplens}{%
  {\normalfont\fontencoding{T2A}\itshape\symbol{'235}}%
}
\DeclareRobustCommand{\ns}{%
  \simplens
  \begin{picture}(0,0)
  \linethickness{0.065ex}
  \roundcap
  \put(-0.225em,0.3ex){\line(1,0){0.215em}}
  \end{picture}%
}

\begin{document}

Some text and \ns~1.

{\Large \ns~4}

\end{document}