Triangular array T read by rows: T(n,0)=T(n,n)=1 for n >= 0; T(2,1)=2; for n >= 3 and 1<=k<=n-1, T(n,k) = T(n-1,k-1) + T(n-2,k-1) + T(n-1,k) if 1<=k<=(n-1)/2, else T(n,k) = T(n-1,k-1) + T(n-1,k).
A026769
Triangular array T read by rows: T(n,0)=T(n,n)=1 for n >= 0; T(2,1)=2; for n >= 3 and 1<=k<=n-1, T(n,k) = T(n-1,k-1) + T(n-2,k-1) + T(n-1,k) if 1<=k<=(n-1)/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) =2a(5) =1a(6) =1a(7) =4a(8) =3a(9) =1a(10) =1a(11) =6a(12) =7a(13) =4a(14) =1a(15) =1a(16) =8a(17) =17a(18) =11a(19) =5a(20) =1a(21) =1a(22) =10a(23) =31a(24) =28a(25) =16a(26) =6a(27) =1a(28) =1a(29) =12
External references
- oeis: A026769