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”).

A316080
Sequence shifts left eight places under Weigh transform with a(n) = signum(n) for n<8.
3
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 3, 4, 5, 6, 8, 10, 13, 17, 22, 30, 40, 53, 71, 96, 128, 173, 233, 314, 425, 575, 780, 1060, 1442, 1964, 2680, 3658, 5000, 6840, 9366, 12835, 17604, 24164, 33194, 45632, 62775, 86417, 119038, 164077, 226287, 312261, 431138
OFFSET
0,12
LINKS
FORMULA
G.f.: x + x^2 + x^3 + x^4 + x^5 + x^6 + x^7 + x^8 * Product_{n>=1} (1 + x^n)^a(n). - Ilya Gutkovskiy, May 09 2019
MAPLE
b:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0,
add(binomial(a(i), j)*b(n-i*j, i-1), j=0..n/i)))
end:
a:= n-> (k-> `if`(n<k, signum(n), b(n-k$2)))(8):
seq(a(n), n=0..53);
CROSSREFS
Column k=8 of A316074.
Sequence in context: A240735 A057042 A063595 * A130082 A241377 A266750
KEYWORD
nonn,eigen
AUTHOR
Alois P. Heinz, Jun 23 2018
STATUS
approved