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-1,k) if k or n-k is of form 2h for h=1,2,...,[ n/4 ], else T(n,k)=T(n-1,k-1)+T(n-2,k-1)+T(n-1,k).

A026681

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-1,k) if k or n-k is of form 2h for h=1,2,...,[ n/4 ], else T(n,k)=T(n-1,k-1)+T(n-2,k-1)+T(n-1,k).

Terms

    a(0) =1a(1) =1a(2) =1a(3) =1a(4) =3a(5) =1a(6) =1a(7) =5a(8) =5a(9) =1a(10) =1a(11) =7a(12) =10a(13) =7a(14) =1a(15) =1a(16) =9a(17) =17a(18) =17a(19) =9a(20) =1a(21) =1a(22) =11a(23) =26a(24) =44a(25) =26a(26) =11a(27) =1a(28) =1a(29) =13

External references