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 A249034 #19 Jul 21 2015 03:01:43
%S A249034 5,13,17,21,29,37,45,49,53,61,65,69,77,81,85,93,101,109,113,117,125,
%T A249034 133,141,145,149,157,165,173,177,181,189,193,197,205,209,213,221,229,
%U A249034 237,241,245,253,257,261,269,273,277,285,293,301,305,309,317,321,325
%N A249034 Odd numbers missing from A171947.
%C A249034 These are the odd terms in A171946.
%C A249034 Consider the sequence of first differences, divided by 4: 2, 1, 1, 2, 2, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 2, 2, 1, 1, 2, 2, 2, ... This is, almost certainly, A026465 without its leading 1. - _N. J. A. Sloane_, Oct 30 2014
%C A249034 This sequence appears to be the same as A260191, Numbers n such that there exists no square whose base-n digit sum is binomial(n,2), without that sequence's leading 3. - _Jon E. Schoenfield_, Jul 19 2015
%H A249034 Reinhard Zumkeller, <a href="/A249034/b249034.txt">Table of n, a(n) for n = 1..10000</a>
%t A249034 f[n_] := Block[{a = {1}, b = {}, k}, Do[k = 2; While[MemberQ[a, k] || MemberQ[b, k], k++]; AppendTo[a, 2 k - 1]; AppendTo[b, k], {i, 2, n}]; a]; Complement[Range[1, Max@ #, 2], #] &@ f@ 120 (* _Michael De Vlieger_, Jul 20 2015 *)
%o A249034 (Haskell)
%o A249034 a249034 n = a249034_list !! (n-1)
%o A249034 a249034_list = filter odd a171946_list
%o A249034 -- _Reinhard Zumkeller_, Oct 26 2014
%Y A249034 Cf. A026465, A171946, A171947, A260191.
%K A249034 nonn
%O A249034 1,1
%A A249034 _N. J. A. Sloane_, Oct 26 2014