login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A245818
Difference in size between rooted trees which are encoded with Matula-Goebel numbers A245822(n) and n: a(n) = A061775(A245822(n)) - A061775(n).
3
0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 2, -1, 2, 0, 0, 1, 0, 1, 2, -1, 0, -1, 2, -1, 1, 0, -1, 0, 2, 1, 2, 1, -1, 0, 1, 1, 2, 0, 0, 2, 2, -1, -1, -1, 0, 1, -1, 1, 0, 2, -1, -1, 1, 0, 3, 0, 0, 0, 3, -1, 0, 0, 0, 1, 3, -2, 0, 0, 0, 1, 2, -1, 2, 3, 0, 2, 2, -4, 1, -1, 1, 3, 4, -1, 0, 0, -2, 1, 0, 1, 1, 0, 0, -1, 1, 1, 0
OFFSET
1,14
LINKS
FORMULA
a(n) = A061775(A245822(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)
\\ Execute first the code given in A061775 and A245822.
for(n=1, 10001, write("b245818.txt", n, " ", A245818(n)));
(Scheme) (define (A245818 n) (- (A061775 (A245822 n)) (A061775 n)))
CROSSREFS
KEYWORD
sign
AUTHOR
Antti Karttunen, Aug 16 2014
STATUS
approved