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 A093918 #16 Jan 25 2021 10:49:57
%S A093918 2,8,11,27,28,58,53,101,86,156,127,223,176,302,233,393,298,496,371,
%T A093918 611,452,738,541,877,638,1028,743,1191,856,1366,977,1553,1106,1752,
%U A093918 1243,1963,1388,2186,1541,2421,1702,2668,1871,2927,2048,3198,2233,3481,2426,3776
%N A093918 a(2k-1)=(2k-1)^2+k, a(2k)=6k^2+k+1: Last term in rows of triangle A093915.
%C A093918 Initially defined as "leading diagonal" of the triangle A093915, a(n) is the last term in row n of A093915, i.e. a(n)=A093916(n)+n-1. - M. F. Hasler, Apr 04 2009
%H A093918 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (0,3,0,-3,0,1).
%F A093918 Equals A093915 o A000217 = A093916 + A023443. - _M. F. Hasler_, Apr 04 2009
%F A093918 a(n) = (3+(-1)^n+2*n+(5+(-1)^n)*n^2)/4. a(n) = 3*a(n-2)-3*a(n-4)+a(n-6). G.f.: -x*(x^2+2*x+2)*(x^3-x^2+3*x+1) / ((x-1)^3*(x+1)^3). - _Colin Barker_, Dec 18 2012
%t A093918 LinearRecurrence[{0,3,0,-3,0,1},{2,8,11,27,28,58},50] (* _Harvey P. Dale_, Oct 22 2013 *)
%o A093918 (PARI) A093918(n)=if(n%2,n^2,6*(n\2)^2)+n\2+1 \\ _M. F. Hasler_, Apr 04 2009
%Y A093918 Cf. A093915, A093916, A093917.
%K A093918 nonn,easy
%O A093918 1,1
%A A093918 _Amarnath Murthy_, Apr 25 2004
%E A093918 Edited and extended beyond a(6) by _M. F. Hasler_, Apr 04 2009