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

A058407

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

Terms

    a(0) =1a(1) =3a(2) =13a(3) =44a(4) =134a(5) =356a(6) =876a(7) =1966a(8) =4146a(9) =8236a(10) =15592a(11) =28252a(12) =49357a(13) =83377a(14) =136837a(15) =218728a(16) =341554a(17) =522064a(18) =782810a(19) =1153180a(20) =1671698a(21) =2387568a(22) =3363738a(23) =4679208a(24) =6433183a(25) =8748119a(26) =11775343a(27) =15699188a(28) =20744108a(29) =27180308

External references