Triangle: m=3; e(n,k,n) = (k + m - 1)*e(n - 1, k, m) + (m*n - k + 1 - m)*e(n - 1, k - 1, m); t(n,k) = e(n,k,m) + e(n,n-k,m).

A156186

Triangle: m=3; e(n,k,n) = (k + m - 1)*e(n - 1, k, m) + (m*n - 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) =30a(8) =30a(9) =1a(10) =1a(11) =159a(12) =360a(13) =159a(14) =1a(15) =1a(16) =1119a(17) =3639a(18) =3639a(19) =1119a(20) =1a(21) =1a(22) =10932a(23) =41262a(24) =57414a(25) =41262a(26) =10932a(27) =1a(28) =1a(29) =136764

External references