A336929 a(n) = A331410(sigma(n)), where A331410 is totally additive with a(2) = 0 and a(p) = 1 + a(p+1) for odd primes.

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

Offset

1,8

Links

Antti Karttunen, Table of n, a(n) for n = 1..65537

Index entries for sequences related to sigma(n)

Formula

Additive with a(p^e) = A331410(sigma(p^e)) = A331410(1+ p + p^2 + ... + p^e).

a(n) = A331410(A000203(n)).

Prog

(PARI)
A331410(n) = { my(f=factor(n)); sum(k=1, #f~, if(2==f[k, 1], 0, f[k, 2]*(1+A331410(f[k, 1]+1)))); };
A336929(n) = A331410(sigma(n));

Crossrefs

Cf. A000203, A331410.

Cf. also A336695, A336927, A336928.

Sequence in context: A276426 A317872 A049340 * A325524 A010269 A366911

Adjacent sequences: A336926 A336927 A336928 * A336930 A336931 A336932

Keyword

nonn

Author

Antti Karttunen, Aug 11 2020

Status

approved