This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A216416 #42 Feb 20 2019 09:56:29 %S A216416 1,0,0,3,0,1,3,0,8,9,0,11,0,0,14,0,0,0,0,0,0,0,0,23,21,0,0,0,0,29,30, %T A216416 0,0,0,0,0,4,0,3,0,0,0,0,0,22,3,0,0,48,0,2,17,0,0,54,0,56,0,0,0,11,0, %U A216416 0,21,0,65,9,0,4,23,0,3,0,0,74,0,0,0,39,0,33,0 %N A216416 a(n) = smallest m such that 2n-1 | 10^m+1, or 0 if no such m exists. %H A216416 V. Raman, <a href="/A216416/b216416.txt">Table of n, a(n) for n = 1..99</a>. %o A216416 (PARI) for(i=0,200,i++;m=0;for(x=1,i,if(((10^x+1))%i==0,m=x;break));print1(m",")) \\ _V. Raman_, Nov 22 2012 %Y A216416 Cf. A002326. %K A216416 nonn %O A216416 1,4 %A A216416 _V. Raman_, Sep 07 2012