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

Author

Vaclav Kotesovec, May 15 2018

Keywords

• nonn
• frac

Examples

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

Links

• Eric Weisstein's World of Mathematics, Dilogarithm.
• Eric Weisstein's World of Mathematics, Polylogarithm.

Crossrefs

Cf. A002548, A304581, A302827.

Programs

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