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 A228046 #15 Feb 24 2025 04:35:55
%S A228046 5,3,5,6,3,6,1,9,4,7,8,0,7,8,7,2,8,4,5,5,7,8,5,0,7,4,8,6,6,4,7,1,8,6,
%T A228046 0,7,0,0,4,3,5,4,9,4,9,6,9,1,0,7,9,6,2,2,7,7,5,5,2,0,9,8,4,9,1,8,8,7,
%U A228046 9,3,3,8,3,3,6,0,7,1,3,2,4,9,7,9,7,8
%N A228046 Decimal expansion of sum of reciprocals of row 4 of the natural number array, A185787.
%C A228046 See A228044.
%F A228046 Equals 1/10 + 1/14 + 1/19 + ...
%F A228046 Equals (1/4340)*(-2573 + 560*r*tanh(r)), where r = (Pi/2)*sqrt(31).
%e A228046 0.5356361947807872845578507486647...
%t A228046 $MaxExtraPrecision = Infinity; t[n_, k_] := t[n, k] = n + (n + k - 2) (n + k - 1)/2; u = N[Sum[1/t[4, k], {k, 1, Infinity}], 130]; RealDigits[u, 10]
%Y A228046 Cf. A185787, A000027, A228044, A226985.
%K A228046 nonn,cons,easy
%O A228046 0,1
%A A228046 _Clark Kimberling_, Aug 06 2013