%I #10 Apr 14 2022 21:46:34

%S 1,2,15,79,420,1744,6197,18715,50042,118121,250025,475791,820987,

%T 1287695,1845875,2423114,2923474,3246721,3327677,3150758,2761802,

%U 2242711,1690526,1183725,771951,469281,267108,142542,71844,34271,15685,6861,2948,1223,513,209,90,34,16,6,3,1,1

%N Number of 7 X 7 binary matrices with n ones, with no zero rows or columns, up to row and column permutation.

%C Sum_{k=0..49} a(n)=A054976(7).

%F G.f. : Z(S_7 X S_7; x_1, x_2, ...)-2*Z(S_7 X S_6; x_1, x_2, ...)+Z(S_6 X S_6; x_1, x_2, ...) if we replace x_i by 1+x^i, where Z(S_i X S_j; x_1, x_2, ...) is cycle index of Cartesian product of symmetric groups S_i and S_j of degree i and j, respectively.

%Y Cf. A053304.

%K fini,full,nonn

%O 7,2

%A _Vladeta Jovovic_, Aug 04 2000

%E More terms from _Sean A. Irvine_, Apr 14 2022