A055194 Number of 3 X n binary matrices with distinct rows, up to row and column permutation; (n,3)-hypergraphs (including empty hyperedge but excluding multiple hyperedges).

3, 16, 52, 134, 302, 614, 1159, 2064, 3504, 5716, 9018, 13818, 20643, 30158, 43190, 60758, 84110, 114746, 154469, 205422, 270132, 351562, 453172, 578962, 733551, 922238, 1151072, 1426932, 1757618, 2151920, 2619731, 3172138, 3821524, 4581682, 5467942, 6497272, 7688431

Offset: 2

Author

Vladeta Jovovic, Jun 30 2000

Keywords

• easy
• nonn

Links

• Index entries for linear recurrences with constant coefficients, signature (4,-4,-2,2,4,3,-12,3,4,2,-2,-4,4,-1).

Crossrefs

Cf. A002727.

Formula

G.f.: -x^2*(x^8-2*x^6-2*x^5+4*x^3-4*x-3)/((x^3-1)^2*(x^2-1)^2*(x-1)^4).

a(n) ~ n^7/30240. - Stefano Spezia, Nov 22 2023

Extensions

More terms from James Sellers, Jul 04 2000

a(35)-a(38) from Stefano Spezia, Nov 22 2023