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

Author

Leroy Quet, Oct 07 2005

Keywords

• nonn

Comments

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

Examples

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

Links

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

Crossrefs

Cf. A001414, A005117, A008472, A265668.

Programs

Haskell

a111060 1 = 0
a111060 n = sum $ a265668_row n -- Reinhard Zumkeller, Dec 13 2015

Mathematica

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

PARI

{for(n=1,113,if(issquarefree(n),f=factor(n)[,1];print1(sum(j=1,length(f),f[j]),",")))}

Formula

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

Extensions

More terms from Klaus Brockhaus, Oct 08 2005