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A255523 Number of rooted identity trees with n n-colored non-root nodes. 3
1, 1, 5, 64, 1193, 30526, 991264, 39156244, 1824927697, 98125181461, 5983042467096, 408095177801851, 30797863537552547, 2548357838769171131, 229445851718471852031, 22334471403618839348901, 2337414940442888593612961, 261737726746663069945238177 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..300

EXAMPLE

a(2) = 5:

o    o    o    o      o

|    |    |    |     / \

1    1    2    2    1   2

|    |    |    |

1    2    1    2

MAPLE

with(numtheory):

A:= proc(n, k) option remember; `if`(n<2, n, add(A(n-j, k)*add(

      k*A(d, k)*d*(-1)^(j/d+1), d=divisors(j)), j=1..n-1)/(n-1))

    end:

a:= n-> A(n+1, n):

seq(a(n), n=0..25);

CROSSREFS

A diagonal of A255517.

Cf. A242375.

Sequence in context: A054937 A302993 A266095 * A193222 A274265 A073179

Adjacent sequences:  A255520 A255521 A255522 * A255524 A255525 A255526

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Feb 24 2015

STATUS

approved

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Last modified July 19 03:54 EDT 2019. Contains 325144 sequences. (Running on oeis4.)