OFFSET
0,3
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..80
FORMULA
a(n) = [x^n] Product_{k=1..n} 1/(1 + x^k)^(k^n). - Ilya Gutkovskiy, Mar 06 2018
PROG
(Ruby)
def s(k, n)
s = 0
(1..n).each{|i| s += (-1) ** (n / i + 1) * i ** k if n % i == 0}
s
end
def A(k, n)
ary = [1]
a = [0] + (1..n).map{|i| s(k + 1, i)}
(1..n).each{|i| ary << (1..i).inject(0){|s, j| s - a[j] * ary[-j]} / i}
ary
end
def A281268(n)
(0..n).map{|i| A(i, i)[-1]}
end
CROSSREFS
KEYWORD
sign
AUTHOR
Seiichi Manyama, Apr 13 2017
STATUS
approved