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