Number of 4 X n binary matrices with no zero rows or columns, up to row and column permutation.

Terms

a(0) =1a(1) =8a(2) =42a(3) =179a(4) =633a(5) =2001a(6) =5745a(7) =15274a(8) =38000a(9) =89331a(10) =199715a(11) =427184a(12) =878152a(13) =1741964a(14) =3345562a(15) =6239390a(16) =11327863a(17) =20065972a(18) =34747460a(19) =58924066a(20) =98002370a(21) =160086580a(22) =257148244a(23) =406637336a(24) =633669040a(25) =973971441a(26) =1477810227a(27) =2215179768a(28) =3282598034a(29) =4811946882