A336695 a(n) = A331410(1+sigma(n)), where A331410 is totally additive with a(2) = 0 and a(p) = 1 + a(p+1) for odd primes.

0, 0, 2, 0, 1, 2, 2, 0, 1, 3, 2, 4, 3, 4, 4, 0, 3, 2, 2, 3, 3, 4, 4, 2, 0, 3, 3, 4, 1, 5, 3, 0, 2, 4, 2, 2, 3, 2, 4, 3, 3, 3, 4, 5, 3, 5, 2, 6, 4, 2, 5, 4, 4, 4, 5, 4, 4, 3, 2, 4, 3, 3, 4, 0, 5, 6, 3, 1, 3, 6, 5, 2, 5, 4, 6, 3, 3, 4, 4, 5, 2, 1, 5, 6, 5, 4, 4, 4, 3, 4, 5, 4, 4, 6, 4, 4, 4, 3, 4, 5, 3, 2, 4, 5, 4

Offset

1,3

Links

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

Index entries for sequences related to sigma(n)

Formula

a(n) = A331410(1+A000203(n)) = A331410(A088580(n)) = A331410(A332459(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)))); };
A336695(n) = A331410(1+sigma(n));

Crossrefs

Cf. A000203, A088580, A324294, A331410, A332459, A336691, A336692, A336693, A336694, A336696.

Sequence in context: A266477 A133121 A091602 * A035465 A096144 A118401

Adjacent sequences: A336692 A336693 A336694 * A336696 A336697 A336698

Keyword

nonn

Author

Antti Karttunen, Jul 31 2020

Status

approved