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 A278927 #12 Dec 23 2018 09:14:21
%S A278927 1,3,38,1116,59392,5004720,613252320,103050420480,22752244279296,
%T A278927 6388491978086400,2223423557203968000,939489529945565491200,
%U A278927 473789563269835667374080,281112352557447776249364480,193857685859605294233907200000,153758529080702011472247521280000
%N A278927 a(n) = permanent M_n where M_n is the n X n matrix m(i,j) = 2*i + j.
%H A278927 Vaclav Kotesovec, <a href="/A278927/b278927.txt">Table of n, a(n) for n = 0..36</a>
%F A278927 a(n) ~ c * d^n * n!^2 / sqrt(n), where d = 3.63208011334048289... and c = 1.47836065972078...
%p A278927 with(LinearAlgebra):
%p A278927 a:= n-> `if`(n=0, 1, Permanent(Matrix(n, (i, j)-> 2*i+j))):
%p A278927 seq(a(n), n=0..16);
%t A278927 Flatten[{1, Table[Permanent[Table[2*i+j, {i, 1, n}, {j, 1, n}]], {n, 1, 15}]}]
%o A278927 (PARI) {a(n) = matpermanent(matrix(n, n, i, j, 2*i+j))}
%o A278927 for(n=0, 20, print1(a(n), ", ")) \\ _Vaclav Kotesovec_, Dec 21 2018
%Y A278927 Cf. A204249.
%K A278927 nonn
%O A278927 0,2
%A A278927 _Vaclav Kotesovec_, Dec 01 2016