A symmetrical recursion triangular sequence: m=4; e(n,k,m)= (2* k + m - 1)e(n - 1, k, m) + (m*n - 2*k + 1 - m)e(n - 1, k - 1, m); t(n,k)=e(n, k, m) + e(n, n - k, m).

A156233

A symmetrical recursion triangular sequence: m=4; e(n,k,m)= (2* k + m - 1)e(n - 1, k, m) + (m*n - 2*k + 1 - m)e(n - 1, k - 1, m); t(n,k)=e(n, k, m) + e(n, n - k, m).

Terms

    a(0) =2a(1) =1a(2) =1a(3) =1a(4) =6a(5) =1a(6) =1a(7) =37a(8) =37a(9) =1a(10) =1a(11) =226a(12) =606a(13) =226a(14) =1a(15) =1a(16) =1565a(17) =7972a(18) =7972a(19) =1565a(20) =1a(21) =1a(22) =13514a(23) =102407a(24) =187824a(25) =102407a(26) =13514a(27) =1a(28) =1a(29) =150753

External references