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 A131586 #7 Jul 06 2021 15:29:17
%S A131586 3,30,304,3042,30424,304248,3042487,30424876,304248761,3042487612,
%T A131586 30424876125,304248761258,3042487612585,30424876125859,
%U A131586 304248761258595,3042487612585951,30424876125859513,304248761258595132
%N A131586 Concatenation of first n numbers of the decimal expansion of imaginary part of 4th nontrivial zero of Riemann zeta function.
%H A131586 <a href="/index/Z#zeta_function">Index entries for zeta function</a>.
%t A131586 Module[{nn=30,zzero},zzero=RealDigits[Im[N[ZetaZero[4],nn]]][[1]];Table[ FromDigits[Take[zzero,n]],{n,nn}]] (* _Harvey P. Dale_, Jul 06 2021 *)
%Y A131586 See A002410 and A065453 for more information.
%K A131586 easy,nonn,base,less
%O A131586 0,1
%A A131586 _Omar E. Pol_, Sep 13 2007