A111060 a(n) = sum of primes dividing the n-th squarefree positive integer.

0, 2, 3, 5, 5, 7, 7, 11, 13, 9, 8, 17, 19, 10, 13, 23, 15, 29, 10, 31, 14, 19, 12, 37, 21, 16, 41, 12, 43, 25, 47, 20, 53, 16, 22, 31, 59, 61, 33, 18, 16, 67, 26, 14, 71, 73, 39, 18, 18, 79, 43, 83, 22, 45, 32, 89, 20, 34, 49, 24, 97, 101, 22, 103, 15, 55, 107, 109, 18, 40, 113

Offset

1,2

Comments

For n > 1: sum of row n in A265668. - Reinhard Zumkeller, Dec 13 2015

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Formula

a(n) = A008472(A005117(n)) = A001414(A005117(n)).

Example

Since the 5th squarefree positive integers is 6 = 2*3, the 5th term of the sequence is 2 + 3 = 5.

Mathematica

Table[DivisorSum[n, # &, PrimeQ], {n, Select[Range@ 113, SquareFreeQ]}] (* Michael De Vlieger, Dec 23 2017 *)

Prog

(PARI) {for(n=1, 113, if(issquarefree(n), f=factor(n)[, 1]; print1(sum(j=1, length(f), f[j]), ", ")))}
(Haskell)
a111060 1 = 0
a111060 n = sum $ a265668_row n -- Reinhard Zumkeller, Dec 13 2015

Crossrefs

Cf. A001414, A005117, A008472, A265668.

Sequence in context: A123318 A186698 A234345 * A082432 A336298 A037153

Adjacent sequences: A111057 A111058 A111059 * A111061 A111062 A111063

Keyword

nonn

Author

Leroy Quet, Oct 07 2005

Extensions

More terms from Klaus Brockhaus, Oct 08 2005

Status

approved