T(n,k) = Sum of multinomial(n; n_1,n_2,...,n_k)^2, where the sum extends over all compositions (n_1,n_2,...,n_k) of n into exactly k nonnegative parts.
A192722
T(n,k) = Sum of multinomial(n; n_1,n_2,...,n_k)^2, where the sum extends over all compositions (n_1,n_2,...,n_k) of n into exactly k nonnegative parts.
Terms
- a(0) =1a(1) =1a(2) =4a(3) =1a(4) =18a(5) =36a(6) =1a(7) =68a(8) =432a(9) =576a(10) =1a(11) =250a(12) =3900a(13) =14400a(14) =14400a(15) =1a(16) =922a(17) =32400a(18) =252000a(19) =648000a(20) =518400a(21) =1a(22) =3430a(23) =262542a(24) =3880800a(25) =19404000a(26) =38102400a(27) =25401600a(28) =1a(29) =12868
External references
- oeis: A192722