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A175318
a(n) = Sum_{k<=n} A007955(k), where A007955(m) = product of divisors of m.
0
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
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
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Apr 01 2010
EXTENSIONS
Edited and more terms from Michel Marcus, Dec 09 2014
STATUS
approved