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 A249245 #5 Oct 28 2014 00:12:23
%S A249245 1,2,4,5,6,8,9,10,12,13,14,16,17,18,20,21,23,24,25,27,28,29,31,32,33,
%T A249245 35,36,37,39,40,42,43,44,46,47,48,50,51,52,54,55,57,58,59,61,62,63,65,
%U A249245 66,67,69,70,71,73,74,76,77,78,80,81,82,84,85,86,88,89
%N A249245 Numbers k such that A249243(k+1) = A249243(k) + 1.
%C A249245 A249244 and A249245 are a complementary pair, analogous to the pair A247785 and A247786.
%H A249245 Clark Kimberling, <a href="/A249245/b249245.txt">Table of n, a(n) for n = 1..5000</a>
%t A249245 u = Floor[Table[1/((1 + 1/n)^(n + 1) - E), {n, 1, 1000}]]; (* A249243 *)
%t A249245 d = Differences[u]
%t A249245 Flatten[Position[d, 0]] (* A249244 *)
%t A249245 Flatten[Position[d, 1]] (* A249245 *)
%Y A249245 Cf. A247784, A247785, A249243, A249244.
%K A249245 nonn,easy
%O A249245 1,2
%A A249245 _Clark Kimberling_, Oct 23 2014