A337346 Number of proper divisors d of n for which A003961(d) > 2*d.

0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 2, 0, 2, 0, 2, 0, 0, 0, 4, 0, 0, 1, 2, 0, 3, 0, 3, 0, 0, 0, 5, 0, 0, 0, 4, 0, 3, 0, 1, 2, 0, 0, 6, 0, 1, 0, 1, 0, 4, 0, 4, 0, 0, 0, 7, 0, 0, 2, 4, 0, 1, 0, 1, 0, 3, 0, 8, 0, 0, 1, 1, 0, 2, 0, 6, 2, 0, 0, 7, 0, 0, 0, 3, 0, 7, 0, 1, 0, 0, 0, 8, 0, 2, 1, 4, 0, 1, 0, 3, 3

Offset: 1

Author

Antti Karttunen, Aug 27 2020

Keywords

• nonn

Comments

Number of terms of A246282 less than n that divide n.

Number of proper divisors d of n for which A048673(d) > d.

Links

• Antti Karttunen, Table of n, a(n) for n = 1..65537
• Index entries for sequences computed from indices in prime factorization

Crossrefs

Cf. A003961, A048673, A246282, A252742, A337345, A337372.

Cf. also A294929.

Programs

PARI

A003961(n) = { my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); };
A337346(n) = sumdiv(n,d,(dA003961(d)>(d+d)));

Formula

a(n) = Sum_{d|n, dA252742(d).

a(n) = A337345(n) - A252742(n).