Triangular array T read by rows: T(n,0)=T(n,n)=1 for n >= 0; for n >= 2 and 1 <= k <= n-1, T(n,k) = T(n-1,k-1) + T(n-2,k-1) + T(n-1,k) if n is even and 1 <= k <= n/2, else T(n,k) = T(n-1,k-1) + T(n-1,k).
A026747
Triangular array T read by rows: T(n,0)=T(n,n)=1 for n >= 0; for n >= 2 and 1 <= k <= n-1, T(n,k) = T(n-1,k-1) + T(n-2,k-1) + T(n-1,k) if n is even and 1 <= k <= n/2, else T(n,k) = T(n-1,k-1) + T(n-1,k).
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =3a(5) =1a(6) =1a(7) =4a(8) =4a(9) =1a(10) =1a(11) =6a(12) =11a(13) =5a(14) =1a(15) =1a(16) =7a(17) =17a(18) =16a(19) =6a(20) =1a(21) =1a(22) =9a(23) =30a(24) =44a(25) =22a(26) =7a(27) =1a(28) =1a(29) =10
External references
- oeis: A026747