Irregular triangular array T read by rows: T(n, 0) = T(n, 2*n) = 1, T(n, 1) = T(n, 2*n-1) = floor(n/2 + 1), for even n >= 2, T(n, k) = T(n-1, k-2) + T(n-1, k-1) + T(n-1, k), otherwise T(n, k) = T(n-1, k-2) + T(n-1, k).

A026552

Irregular triangular array T read by rows: T(n, 0) = T(n, 2*n) = 1, T(n, 1) = T(n, 2*n-1) = floor(n/2 + 1), for even n >= 2, T(n, k) = T(n-1, k-2) + T(n-1, k-1) + T(n-1, k), otherwise T(n, k) = T(n-1, k-2) + T(n-1, k).

Terms

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

External references