A318853 Number of rooted trees with n nodes such that no more than six isomorphic subtrees extend from the same node.

0, 1, 1, 2, 4, 9, 20, 48, 114, 284, 714, 1829, 4731, 12391, 32711, 87083, 233347, 629132, 1705026, 4642964, 12696279, 34851400, 95996673, 265251812, 735029389, 2042187079, 5687726124, 15876511622, 44409196932, 124459720195, 349434222059, 982723600768

Offset

0,4

Links

Alois P. Heinz, Table of n, a(n) for n = 0..2136

Maple

h:= proc(n, m, t) option remember; `if`(m=0, binomial(n+t, t),
      `if`(n=0, 0, add(h(n-1, m-j, t+1), j=1..min(6, m))))
    end:
b:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0,
      add(b(n-i*j, i-1)*h(a(i), j, 0), j=0..n/i)))
    end:
a:= n-> `if`(n<2, n, b(n-1$2)):
seq(a(n), n=0..35);

Crossrefs

Column k=6 of A318757.

Sequence in context: A036626 A036722 A318800 * A255637 A215796 A034824

Adjacent sequences: A318850 A318851 A318852 * A318854 A318855 A318856

Keyword

nonn

Author

Alois P. Heinz, Sep 04 2018

Status

approved