A109353 a(n) is the sum of the distinct prime divisors of A024619(n).

5, 7, 5, 9, 8, 5, 7, 10, 13, 5, 15, 9, 10, 14, 19, 12, 5, 21, 16, 7, 12, 13, 8, 25, 5, 7, 20, 15, 5, 16, 9, 22, 31, 10, 33, 10, 18, 16, 19, 26, 14, 5, 39, 8, 21, 18, 18, 7, 43, 12, 22, 45, 32, 13, 10, 20, 25, 34, 49, 24, 5, 9, 14, 7, 22, 15, 15, 55, 5, 18, 40, 9, 24, 28, 31, 16, 61, 24

Offset

1,1

Links

Table of n, a(n) for n=1..78.

Example

a(3)=5 because the 3rd non-prime-power is 12 and its prime factors sum to 5.

Prog

(PARI) distinct(n) = \sum the distinct prime factors of n { local(a, x, m, ln, s); for(m=2, n, s=0; a=ifactord(m); ln=length(a); if(ln > 1, for(x=1, ln, s+=a[x]; ); print1(s", ") ) ) } ifactord(n, m=0) = \distinct prime factors of n { local(f, j, k, flist); flist=[]; f=Vec(factor(n, m)); for(j=1, length(f[1]), flist = concat(flist, f[1][j]) ); return(flist) }

Crossrefs

Cf. A024619.

Sequence in context: A195498 A065746 A065478 * A247827 A205694 A121595

Adjacent sequences: A109350 A109351 A109352 * A109354 A109355 A109356

Keyword

easy,nonn

Author

Cino Hilliard, Aug 21 2005

Extensions

Edited by Don Reble, Jul 23 2006

Status

approved