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 A231626 #11 Jul 16 2025 19:05:39
%S A231626 1,7,13,31,43,49,61,73,91,115,121,127,133,145,151,163,169,181,187,211,
%T A231626 229,235,241,247,253,265,283,289,295,313,325,331,343,347,355,373,385,
%U A231626 403,409,421,427,433,451,469,481,505,511,523,535,553,565,583,589,595
%N A231626 Smallest sets of 5 consecutive deficient numbers in arithmetic progression. The initial deficient number is listed.
%H A231626 Shyam Sunder Gupta, <a href="/A231626/b231626.txt">Table of n, a(n) for n = 1..5000</a>
%e A231626 1, 2, 3, 4, 5 is the smallest set of 5 consecutive deficient numbers in arithmetic progression so 1 is in the list.
%t A231626 DefQ[n_] := DivisorSigma[1, n] < 2 n; m = 2; z1 = 2; cd = 1; a = {}; Do[If[DefQ[n], If[n - z1 == cd, m = m + 1; If[m > 4, AppendTo[a, n - 4*cd]], m = 2; cd = n - z1]; z1 = n], {n, 3, 1000000}]; a
%Y A231626 Cf. A005100, A231623, A228962, A231624, A231625.
%K A231626 nonn
%O A231626 1,2
%A A231626 _Shyam Sunder Gupta_, Nov 11 2013