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 A071120 #20 Feb 16 2025 08:32:46
%S A071120 2,0,9,3,1,7,0,4,5,9,1,9,5,4,9,0,8,9,3,9,6,8,2,0,1,3,7,0,1,4,5,2,0,8,
%T A071120 3,2,5,6,8,9,5,9,2,1,6,7,8,9,1,1,5,4,5,1,9,0,6,9,1,9,6,7,2,1,5,1,8,1,
%U A071120 8,7,0,3,3,4,9,9,8,3,3,5,9,6,0,4,7,6,7,5,2,0,9,4,4,4,5,2,4,0,4
%N A071120 Decimal expansion of Sum_{n >= 1} 1/S(n)!, where S(n) is the Kempner number A002034.
%C A071120 Computed using suggestions from _David W. Wilson_ posted to Sequence Fans mailing list (seqfan(AT)ext.jussieu.fr), May 30 2002
%D A071120 I. Cojocaru, S. Cojocaru, First Constant of Smarandache, Smarandache Notions Journal, Vol. 7, No. 1-2-3, 1996, 116-118.
%H A071120 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/SmarandacheConstants.html">Smarandache Constants</a>
%F A071120 Sum_{n>=1} 1/S(n)!, where S(n) is the Kempner function A002034.
%F A071120 Sum_{n>=1} A038024(n)/n!, where A038024(n) = #{k: S(k) = n}. - _Jonathan Sondow_, Aug 21 2006
%F A071120 Equals 1+A048799.
%e A071120 2.09317...
%t A071120 f[n_] := DivisorSigma[0, n! ]; s = 1; Do[s = N[s + (f[n + 1] - f[n])/(n + 1)!, 100], {n, 1, 10^4}]; RealDigits[s][[1]]
%Y A071120 Cf. A048799, A002034, A048834, A038024, A092495.
%K A071120 nonn,cons
%O A071120 1,1
%A A071120 Charles T. Le (charlestle(AT)yahoo.com)
%E A071120 Edited by _Robert G. Wilson v_ and _Don Reble_, May 30 2002