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 A086951 #11 Apr 10 2023 10:25:40
%S A086951 0,1,14,99,540,2565,11178,45927,180792,688905,2558790,9310059,
%T A086951 33303636,117448461,409209570,1410975855,4821232752,16343405073,
%U A086951 55013709438,184024732275,612124372620,2025821736981,6673705343514,21893519253879,71548815908520,233004367596825
%N A086951 a(n) = n*3^n*(4*n - 1)/9.
%H A086951 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (9,-27,27).
%F A086951 G.f.: x*(1 + 5*x)/(1 - 3*x)^3.
%F A086951 E.g.f.: exp(3*x)*x*(1 + 4*x). - _Stefano Spezia_, Oct 09 2022
%t A086951 LinearRecurrence[{9,-27,27},{0,1,14},30] (* _Harvey P. Dale_, Apr 10 2023 *)
%Y A086951 Binomial transform of A086950. Second binomial transform of decagonal numbers A001107. Binomial transform is A086952.
%K A086951 easy,nonn
%O A086951 0,3
%A A086951 _Paul Barry_, Jul 24 2003