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 A131493 #17 Mar 19 2015 09:38:16 %S A131493 3,226,1837,2163,5358,44857,170788,482721,8918391,36589396,122394502, %T A131493 1107852077,10071260304,22991513047,81477190549,422242473309, %U A131493 4242315932866,153777057499935,282960008506695,1683262946768556,1099372130016731506,1117679864051418714 %N A131493 Values of n such that Pi^n starts with the digits n. %e A131493 226 is a term of this sequence because Pi^226 = 226.9191... * 10^110, which starts with 226. %o A131493 (PARI) s=1;for(i=1,10000000,s=s*Pi; if(s-i>11,s=s/10,); if(floor(s)==i,printp1(i,", "),)) %Y A131493 Cf. A100129, A131494 %K A131493 nonn,base %O A131493 1,1 %A A131493 _Randy L. Ekl_, Aug 12 2007 %E A131493 a(10)-a(12) from _Jon E. Schoenfield_, Jul 17 2010 %E A131493 a(13)-a(22) from _Max Alekseyev_, Sep 12 2013