%I #13 Sep 15 2019 04:07:06
%S 1,5,53,458,3411,19865,95214,383714,1346183,4202086,11905966,31061806,
%T 75533056,172800689,374861365,775978710,1541027694,2949003213,
%U 5458806804,9805626744,17140511056
%N Number of 4 X 4 matrices with nonnegative integer entries and all row sums equal to n, up to row and column permutation.
%H Andrew Howroyd, <a href="/A058390/b058390.txt">Table of n, a(n) for n = 0..1000</a>
%H Vladeta Jovovic, <a href="/A058389/a058389a.pdf">Number of m x m nonnegative integer matrices with all row sums equal to n, up to row and column permutation.</a>
%t (* See A318951 for RowSumMats *)
%t a[n_] := RowSumMats[4, 4, n];
%t a /@ Range[0, 20] (* _Jean-François Alcover_, Sep 15 2019, after _Andrew Howroyd_ *)
%o (PARI) \\ See A318951 for RowSumMats
%o a(n)=RowSumMats(4, 4, n); \\ _Andrew Howroyd_, Sep 05 2018
%Y Row 4 of A318951.
%Y Cf. A002620, A058389, A058391, A058392, A001496, A052280, A052281.
%K nonn
%O 0,2
%A _Vladeta Jovovic_, Nov 24 2000