A336928 a(n) = A329697(sigma(n)), where A329697 is totally additive with a(2) = 0 and a(p) = 1 + a(p-1) for odd primes.

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

Offset

1,4

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) = A329697(sigma(p^e)) = A329697(1+ p + p^2 + ... + p^e).

a(n) = A329697(A000203(n)).

Prog

(PARI)
A329697(n) = { my(f=factor(n)); sum(k=1, #f~, if(2==f[k, 1], 0, f[k, 2]*(1+A329697(f[k, 1]-1)))); };
A336928(n) = A329697(sigma(n));

Crossrefs

Cf. A000203, A329697.

Cf. also A336469, A336694, A336927, A336929.

Sequence in context: A235141 A347386 A331410 * A366388 A114638 A123340

Adjacent sequences: A336925 A336926 A336927 * A336929 A336930 A336931

Keyword

nonn

Author

Antti Karttunen, Aug 11 2020

Status

approved