3,1

G. f.: (1/(1-x)^16-6/(1-x)^8/(1-x^2)^4-3/(1-x)^4/(1-x^2)^6+8/(1-x)^4/(1-x^3)^4+2/(1-x)^2/(1-x^2)^3/(1-x^4)^2+6/(1-x)^4/(1-x^2)^4/(1-x^4)-8/(1-x)^2/(1-x^4)^2/(1-x^6))/24

There are 7 asymmetric (4,3)-hypergraphs: {{1,2},{1,2,3},{1,3,4}}, {{1,2},{1,3},{1,2,4}}, {{1,2},{1,2},{1,3}}, {{1},{1,2},{1,2,3}}, {{1},{2,3},{1,2,4}}, {{1},{1,2},{2,3}}, {{1},{2},{1,3}}.

Cf. A006148.

Sequence in context: A116231 A136955 A027767 this_sequence A098307 A055995 A008787

Adjacent sequences: A055534 A055535 A055536 this_sequence A055538 A055539 A055540

nonn

Vladeta Jovovic (vladeta(AT)Eunet.yu), Jul 09 2000

More terms from James A. Sellers (sellersj(AT)math.psu.edu), Jul 11 2000