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 A226120 #20 Feb 16 2025 08:33:19
%S A226120 1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,9,0,1,6,1,7,6,7,8,8,8,6,6,2,6,7,
%T A226120 5,5,8,4,3,5,9,3,0,5,8,5,5,4,4,5,3,3,3,4,8,0,2,5,4,8,9,7,8,4,3,4,0,6,
%U A226120 1,0,9,9,4,3,8,7,3,7,8,5,0,6,7,1,4,8,0,1,7,9,1,6,2,7,1,3,6,6,2,1
%N A226120 Decimal expansion of Sum_{n>=1} n^3/(exp(2*Pi*n/7)-1).
%C A226120 An almost-integer discovered by Simon Plouffe. The computed sum equals 10 within 15 digits.
%H A226120 Simon Plouffe, <a href="http://www.plouffe.fr">Simon Plouffe Home Page</a>
%H A226120 Eric Weisstein's MathWorld, <a href="https://mathworld.wolfram.com/AlmostInteger.html">Almost Integer</a>
%e A226120 10.00000000000000019016176788866267558435930585544533348025489784340610994387...
%t A226120 NSum[n^3/(Exp[2*Pi*n/7] - 1), {n, 1, Infinity}, NSumTerms -> 220, WorkingPrecision -> 100] // RealDigits[#, 10, 100] & // First
%Y A226120 Cf. A060295 (famous almost-integer: Ramanujan's constant), A226121 (another surprising almost-integer by Simon Plouffe), A007775, A089034.
%K A226120 nonn,cons
%O A226120 2,19
%A A226120 _Jean-François Alcover_, May 27 2013
%E A226120 Offset corrected by _Rick L. Shepherd_, Jan 01 2014