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A347398
Expansion of g.f. Sum_{k>=1} k^k * x^(k^k)/(1 - x^(k^k)).
2
1, 1, 1, 5, 1, 1, 1, 5, 1, 1, 1, 5, 1, 1, 1, 5, 1, 1, 1, 5, 1, 1, 1, 5, 1, 1, 28, 5, 1, 1, 1, 5, 1, 1, 1, 5, 1, 1, 1, 5, 1, 1, 1, 5, 1, 1, 1, 5, 1, 1, 1, 5, 1, 28, 1, 5, 1, 1, 1, 5, 1, 1, 1, 5, 1, 1, 1, 5, 1, 1, 1, 5, 1, 1, 1, 5, 1, 1, 1, 5, 28, 1, 1, 5, 1, 1, 1, 5, 1, 1, 1, 5, 1, 1, 1, 5, 1, 1, 1, 5, 1, 1, 1, 5, 1, 1, 1, 32, 1, 1, 1, 5
OFFSET
1,4
LINKS
FORMULA
a(n) = A347397(n) - A347397(n-1) for n > 1.
a(n) = Sum_{k=1..n, k^k | n} k^k.
EXAMPLE
1^1 | 108, 2^2 | 108 and 3^3 | 108. So a(108) = 1^1 + 2^2 + 3^3 = 32.
PROG
(PARI) a(n) = sum(k=1, n, (n%k^k==0)*k^k);
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Aug 30 2021
STATUS
approved