A245817 - OEIS

A245817

Difference in size between rooted trees which are encoded as Matula-Goebel numbers A245821(n) and n: a(n) = A061775(A245821(n)) - A061775(n).

0, 0, 0, 0, 0, 1, 0, 0, -1, 0, 0, 1, 1, 4, 0, 0, 0, 1, 0, 4, 1, 1, -1, 0, -2, 1, -1, 1, 0, 1, 0, 4, -2, 0, 1, 0, 1, 2, -1, 1, 1, 2, 4, 1, 0, 3, 0, 0, 1, -2, 2, -1, 0, -1, -2, 1, 2, 0, 0, 1, 1, 3, 0, 0, 0, -1, 0, 5, 0, -2, 4, 2, 1, 3, 0, 0, -1, 3, 1, 1, 0, 5, -1, 1, -1, 2, 1, 1, 0, 4, -1, 0, -2, 0, 3, 5, -2, -1, 0

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OFFSET

1,14

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..10001

FORMULA

a(n) = A061775(A245821(n)) - A061775(n).

Other identities. For all n >= 1, the following holds:

a(A000040(n)) = a(n). [The result for the n-th prime is same as for n itself].

a(A245823(n)) = 0. [A245823 gives a (proper) subsequence of the positions of the zeros].

PROG

(PARI)