Number of 4 X n nonnegative integer matrices with all column sums 3, up to row and column permutation.

A058409

Number of 4 X n nonnegative integer matrices with all column sums 3, up to row and column permutation.

Terms

    a(0) =1a(1) =3a(2) =18a(3) =92a(4) =458a(5) =1982a(6) =7928a(7) =28592a(8) =95138a(9) =292993a(10) =845027a(11) =2295322a(12) =5915631a(13) =14535676a(14) =34224682a(15) =77510148a(16) =169459010a(17) =358698558a(18) =737106306a(19) =1473867060a(20) =2873564862a(21) =5472731212a(22) =10198198452a(23) =18621343624a(24) =33361303957a(25) =58713103696

External references