Irregular triangle read by rows: T(n,k) = number of trees on n nodes with radius k, n>=1, 1 <= k <= floor(n/2).

A283826

Irregular triangle read by rows: T(n,k) = number of trees on n nodes with radius k, n>=1, 1 <= k <= floor(n/2).

Terms

    a(0) =0a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =2a(7) =1a(8) =4a(9) =1a(10) =1a(11) =7a(12) =3a(13) =1a(14) =11a(15) =10a(16) =1a(17) =1a(18) =17a(19) =25a(20) =4a(21) =1a(22) =25a(23) =61a(24) =18a(25) =1a(26) =1a(27) =36a(28) =132a(29) =61

External references