Triangle T(n,t) read by rows: the number of n X n {0,1} matrices with trace t where each row sum and each column sum is 3.
A284990
Triangle T(n,t) read by rows: the number of n X n {0,1} matrices with trace t where each row sum and each column sum is 3.
Terms
- a(0) =1a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =0a(8) =0a(9) =1a(10) =1a(11) =0a(12) =6a(13) =8a(14) =9a(15) =44a(16) =210a(17) =420a(18) =610a(19) =540a(20) =216a(21) =7570a(22) =33120a(23) =66870a(24) =82080a(25) =66870a(26) =33120a(27) =7570a(28) =1975560a(29) =8171730
External references
- oeis: A284990