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 A026293 #6 Sep 24 2019 21:21:09 %S A026293 1,2,14,106,834,6732,55289,459742,3858524,32618022,277326906, %T A026293 2369003910,20315879480,174798617778,1508225204024,13045333585950, %U A026293 113076177711662,981982906771978,8542048596893910,74416362792323370,649168980344148876,5669882132589477798 %N A026293 a(n) = T(3n,n), where T is the array in A026268. %K A026293 nonn %O A026293 0,2 %A A026293 _Clark Kimberling_ %E A026293 a(5) corrected and more terms from _Sean A. Irvine_, Sep 24 2019