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A120287 Numerator of 1/n^3 + 2/(n-1)^3 + 3/(n-2)^3 +...+ (n-1)/2^3 + n. 0
1, 17, 355, 7715, 203413, 492527, 49601051, 1823359051, 16684019407, 186004308017, 22757931053507, 298630937704541, 50872538998767329, 51223731720255509, 103063783892301061, 7045407930432340853 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

p divides a(p-1) and a(p-2) for prime p>3.

LINKS

Table of n, a(n) for n=1..16.

FORMULA

a(n) = numerator[Sum[Sum[1/i^3,{i,1,k}],{k,1,n}]].

MATHEMATICA

Numerator[Table[Sum[Sum[1/i^3, {i, 1, k}], {k, 1, n}], {n, 1, 25}]]

CROSSREFS

Cf. A001008, A007406, A007407, A007408, A007410.

Sequence in context: A194729 A081421 A121824 * A222678 A293691 A002197

Adjacent sequences:  A120284 A120285 A120286 * A120288 A120289 A120290

KEYWORD

frac,nonn

AUTHOR

Alexander Adamchuk, Jul 07 2006

STATUS

approved

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Last modified September 20 04:18 EDT 2020. Contains 337264 sequences. (Running on oeis4.)