A258102 Decimal expansion of Sum_{k >= 1} k^(-k^2).

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

Offset: 1

Author

Jean-François Alcover, May 20 2015

Keywords

• nonn
• cons
• easy

Examples

			1.06255080549625593786944593879337586328548415733862632010781...
		

Links

• G. C. Greubel, Table of n, a(n) for n = 1..1000
• MathOverflow, What is a "generalized zeta function"?

Crossrefs

Cf. A073009.

Programs

Maple

evalf(Sum(k^(-k^2), k=1..infinity), 120); # Vaclav Kotesovec, May 21 2015

Mathematica

NSum[k^(-k^2), {k, 1, Infinity}, WorkingPrecision -> 105] // RealDigits // First

PARI

default(realprecision,120); sumpos(k=1, k^(-k^2)) \\ Vaclav Kotesovec, May 21 2015