Triangle T(n,k) read by rows: number of k X k symmetric matrices with nonnegative integer entries and without zero rows or columns such that sum of all entries is equal to n, n>=1, 1<=k<=n.
A138177
Triangle T(n,k) read by rows: number of k X k symmetric matrices with nonnegative integer entries and without zero rows or columns such that sum of all entries is equal to n, n>=1, 1<=k<=n.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =1a(4) =4a(5) =4a(6) =1a(7) =7a(8) =15a(9) =10a(10) =1a(11) =10a(12) =36a(13) =52a(14) =26a(15) =1a(16) =14a(17) =74a(18) =176a(19) =190a(20) =76a(21) =1a(22) =18a(23) =132a(24) =460a(25) =810a(26) =696a(27) =232a(28) =1a(29) =23
External references
- oeis: A138177