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 A160502 #13 Jul 14 2020 10:48:19
%S A160502 1,4,6,2,5,9,0,7,3,5,0,4,4,3,6,4,6,9,9,5,4,6,1,4,5,4,4,6,7,2,0,5,3,4,
%T A160502 6,2,1,0,7,4,7,4,4,8,6,4,7,4,8,8,2,1,1,0,9,3,6,4,2,0,0,6,2,4,3,5,4,5,
%U A160502 2,2,9,4,3,7,8,5,8,8,1,5,0,3,5,5,2,1,9,2,9,2,2,1,5,9,2,4,0,8,9,2,3,6,9,7,5
%N A160502 Decimal expansion of the (finite) value of Sum_{ k >= 1, k has only a single zero digit in base 2 } 1/k.
%C A160502 The sum of 1/n where n has a single 0 in base 2.
%H A160502 Robert Baillie, <a href="https://arxiv.org/abs/0806.4410">Summing The Curious Series Of Kempner And Irwin</a>, arXiv:0806.4410 [math.CA], 2008-2015.
%F A160502 Equals Sum_{n>=2} Sum_{k=0..n-2}, 1/(2^n - 1 - 2^k).
%e A160502 1.4625907350443646995461454467205346210747448647488211093642006243545229...
%t A160502 RealDigits[ N[ Sum[1/(2^n - 1 - 2^k), {n, 2, 400}, {k, 0, n - 2}], 111]][[1]]
%t A160502 (* first install irwinSums.m, see reference, then *) First@ RealDigits@ iSum[0, 1, 111, 2] (* _Robert G. Wilson v_, Aug 03 2010 *)
%Y A160502 Cf. A030130 (numbers with a single zero in base 2), A140502.
%K A160502 base,cons,nonn
%O A160502 1,2
%A A160502 _Robert G. Wilson v_, May 15 2009