A193526 Sum of even divisors of sopf(n).

0, 2, 0, 2, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 14, 2, 0, 0, 0, 0, 12, 0, 0, 0, 0, 0, 0, 0, 0, 12, 0, 2, 16, 0, 24, 0, 0, 0, 30, 0, 0, 24, 0, 0, 14, 0, 0, 0, 0, 0, 36, 0, 0, 0, 30, 0, 24, 0, 0, 12, 0, 0, 12, 2, 26, 30, 0, 0, 28, 16, 0, 0, 0, 0, 14, 0, 26, 26, 0, 0

Offset

1,2

Comments

Sopf(n) is the sum of the distinct primes dividing n (A008472).

Links

Antti Karttunen, Table of n, a(n) for n = 1..20000

Formula

a(1) = 0; for n > 1, a(n) = A146076(A008472(n)). - Antti Karttunen, Dec 23 2018

Mathematica

Table[Total[Select[Divisors[Plus @@ First[Transpose[FactorInteger[n]]]], EvenQ[#] &]], {n, 100}]

Prog

(PARI)
A008472(n) = vecsum(factor(n)[, 1]); \\ From A008472
A146076(n) = if (n%2, 0, 2*sigma(n/2)); \\ From A146076
A193526(n) = if(1==n, 0, A146076(A008472(n))); \\ Antti Karttunen, Dec 23 2018

Crossrefs

Cf. A008472, A146076, A193525.

Sequence in context: A359893 A218855 A069517 * A160498 A089800 A079208

Adjacent sequences: A193523 A193524 A193525 * A193527 A193528 A193529

Keyword

nonn,easy

Author

Michel Lagneau, Jul 29 2011

Status

approved