A245125 Number of n-node rooted identity trees with thinning limbs and root outdegree (branching factor) 6.

2, 6, 23, 60, 162, 397, 960, 2223, 5085, 11355, 25088, 54654, 118051, 252601, 536973, 1133925, 2382281, 4980512, 10370545, 21512821, 44483291, 91708748, 188580249, 386854596, 791909788, 1617922147, 3299701619, 6718766927, 13660421145, 27736326713, 56246087592

Offset

20,1

Links

Alois P. Heinz, Table of n, a(n) for n = 20..500

Maple

b:= proc(n, i, h, v) option remember; `if`(n=0, `if`(v=0, 1, 0),
      `if`(i<1 or v<1 or n<v, 0, add(binomial(A(i, min(i-1, h)), j)
       *b(n-i*j, i-1, h, v-j), j=0..min(n/i, v))))
    end:
A:= proc(n, k) option remember;
      `if`(n<2, n, add(b(n-1$2, j$2), j=1..min(k, n-1)))
    end:
a:= n-> b(n-1$2, 6$2):
seq(a(n), n=20..55);

Crossrefs

Column k=6 of A245120.

Sequence in context: A168270 A222761 A298817 * A290954 A220213 A217200

Adjacent sequences: A245122 A245123 A245124 * A245126 A245127 A245128

Keyword

nonn

Author

Alois P. Heinz, Jul 12 2014

Status

approved