A056080 - OEIS

%I #9 May 10 2013 12:44:30

%S 1,2,14,49,131,248,410,531,601,566,474,336,222,124,67,32,16,6,3,1,1

%N Number of 5 X 5 binary matrices with n ones, with no zero rows or columns, up to row and column permutation.

%C Sum_{k=0..25} a(n)=A054976(5).

%F G.f. : Z(S_5 X S_5; x_1, x_2, ...)-2*Z(S_5 X S_4; x_1, x_2, ...)+Z(S_4 X S_4; 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. A052371.

%K fini,full,nonn

%O 5,2

%A _Vladeta Jovovic_, Aug 04 2000