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 A106389 #18 Jun 17 2017 03:09:37
%S A106389 1,11,14,24,27,37,40,50,53,63,66,76,79,89,92,102,105,115,118,128,131,
%T A106389 141,144,154,157,167,170,180,183,193,196,206,209,219,222,232,235,245,
%U A106389 248,258,261,271,274,284,287,297,300,310,313,323,326,336,339,349,352
%N A106389 Numbers j such that 6j^2 + 6j + 1 = 13k.
%H A106389 Harvey P. Dale, <a href="/A106389/b106389.txt">Table of n, a(n) for n = 1..1000</a>
%H A106389 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (1,1,-1).
%F A106389 j(1)=1, j(2)=11; then j(n)=j(n-2)+13.
%F A106389 a(n) = (-15+7*(-1)^n+26*n)/4. G.f.: x*(2*x^2+10*x+1) / ((x-1)^2*(x+1)). - _Colin Barker_, Apr 16 2014
%t A106389 fQ[n_] := IntegerQ[(6n(n + 1) + 1)/13]; Select[ Range[ 361], fQ[ # ] &] (* _Robert G. Wilson v_, May 02 2005 *)
%t A106389 LinearRecurrence[{1,1,-1},{1,11,14},60] (* _Harvey P. Dale_, Jun 07 2016 *)
%o A106389 (PARI) Vec((2*x^2+10*x+1)/((x-1)^2*(x+1)) + O(x^100)) \\ _Colin Barker_, Apr 16 2014
%Y A106389 Cf. A106387, A106388, A106390.
%Y A106389 For k sequence see A106390.
%K A106389 nonn,easy
%O A106389 1,2
%A A106389 _Pierre CAMI_, May 01 2005
%E A106389 More terms from _Robert G. Wilson v_, May 02 2005