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 A113015 #12 Feb 16 2025 08:32:59
%S A113015 1,6,116,1928,27665,364472,4547586,54670463,639838113,7338610159,
%T A113015 82857366967
%N A113015 Number of decimal digits in B(10^n) where B(k) is the k-th Bell number.
%H A113015 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/BellNumber.html">Bell Number</a>
%F A113015 a(n) ~ 10^n * n. - _Charles R Greathouse IV_, Aug 11 2011
%t A113015 f[n_] := Sum[ StirlingS2[n, k], {k, n}]; Table[ Length[ IntegerDigits[ f[10^n]]], {n, 0, 4}] (* _Robert G. Wilson v_, Oct 12 2005 *)
%Y A113015 Cf. A000110.
%K A113015 nonn,base
%O A113015 0,2
%A A113015 _Eric W. Weisstein_, Oct 10 2005
%E A113015 a(5)-a(10) from _Charles R Greathouse IV_, Aug 11 2011