A200089 Decimal expansion of sum of reciprocals of squares of partition numbers.

1, 4, 3, 8, 6, 9, 2, 9, 4, 3, 2, 8, 8, 2, 2, 6, 4, 4, 3, 9, 2, 8, 2, 5, 3, 6, 9, 6, 2, 0, 3, 7, 4, 9, 1, 4, 2, 8, 5, 1, 7, 2, 3, 1, 9, 3, 7, 9, 6, 1, 0, 8, 4, 4, 0, 4, 3, 6, 3, 4, 1, 6, 9, 7, 3, 2, 3, 4, 4, 5, 6, 2, 6, 6, 2, 8, 4, 1, 1, 4, 1, 2, 4, 8, 2, 0, 5, 7, 1, 7, 3, 8, 1, 6, 7, 0, 8, 8, 3, 1, 3, 8, 5, 2, 7

Offset: 1

Author

Arkadiusz Wesolowski, Nov 17 2011

Keywords

• cons
• nonn

Links

• Vaclav Kotesovec, Table of n, a(n) for n = 1..2000
• Eric Weisstein's World of Mathematics, Partition Function P

Crossrefs

Cf. A001255.

Programs

Mathematica

RealDigits[N[Sum[1/PartitionsP[i]^2, {i, 2632}], 105]][[1]] (* Arkadiusz Wesolowski, Jan 29 2012 *)

Formula

Sum_{n=1..inf} 1/(A000041(n))^2 = 1.438692943288226443928253696....