A304582 Denominator of Sum_{k=1..n-1} 1/(k*(n-k))^2.

1, 1, 1, 2, 144, 72, 64800, 1800, 2822400, 3175200, 317520000, 635040, 11064936960, 15367968, 2545242860160, 14609174580000, 8310997094400, 259718659200, 24319016372851200, 75058692508800, 10838475198270720000, 2389883781218693760, 374701571140216320

Offset

0,4

Links

Table of n, a(n) for n=0..22.

Eric Weisstein's World of Mathematics, Dilogarithm.

Eric Weisstein's World of Mathematics, Polylogarithm.

Example

0, 0, 1, 1/2, 41/144, 13/72, 8009/64800, 161/1800, 190513/2822400, ...

Mathematica

CoefficientList[Series[PolyLog[2, x]^2, {x, 0, 25}], x]//Denominator
Table[Sum[1/(k*(n - k))^2, {k, 1, n - 1}], {n, 0, 25}]//Denominator

Crossrefs

Cf. A002548, A304581, A302827.

Sequence in context: A101827 A283097 A371588 * A320061 A282296 A163275

Adjacent sequences: A304579 A304580 A304581 * A304583 A304584 A304585

Keyword

nonn,frac

Author

Vaclav Kotesovec, May 15 2018

Status

approved