A175318 a(n) = Sum_{k<=n} A007955(k), where A007955(m) = product of divisors of m.

1, 3, 6, 14, 19, 55, 62, 126, 153, 253, 264, 1992, 2005, 2201, 2426, 3450, 3467, 9299, 9318, 17318, 17759, 18243, 18266, 350042, 350167, 350843, 351572, 373524, 373553, 1183553, 1183584, 1216352, 1217441, 1218597, 1219822, 11297518, 11297555, 11298999, 11300520

Offset

1,2

Links

Table of n, a(n) for n=1..39.

Example

For n = 4, with b(n) = A007955(n), a(4) = b(1)+b(2)+b(3)+b(4) = 1+2+3+8 = 14.

Prog

(PARI) prd(n) = my(dn = divisors(n)); prod(i=1, #dn, dn[i]);
a(n) = sum(k=1, n, prd(k)); \\ Michel Marcus, Dec 09 2014

Crossrefs

Cf. A007955.

Sequence in context: A369304 A083356 A096337 * A281025 A109757 A075189

Adjacent sequences: A175315 A175316 A175317 * A175319 A175320 A175321

Keyword

nonn

Author

Jaroslav Krizek, Apr 01 2010

Extensions

Edited and more terms from Michel Marcus, Dec 09 2014

Status

approved