A257898 Decimal expansion of Sum_{n=2..infinity} (-1)^n/log(log(n)), negated.

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

Offset

2,3

Comments

A very slowly convergent series, converging in virtue of Leibniz's rule.

Links

Table of n, a(n) for n=2..110.

Eric Weisstein's World of Mathematics, Leibniz Criterion

Wikipedia, Alternating series test

Example

-11.47796801398707591150778896756796191665188684328765...

Maple

evalf(sum((-1)^n/log(log(n)), n = 2..infinity), 120);

Mathematica

NSum[(-1)^n/Log[Log[n]], {n, 2, Infinity}, AccuracyGoal -> 120, Method -> "AlternatingSigns", WorkingPrecision -> 200]

Prog

(PARI) default(realprecision, 120); sumalt(n=2, (-1)^n/log(log(n)))

Crossrefs

Cf. A099769, A257837, A257812.

Sequence in context: A070326 A103711 A199435 * A333286 A159919 A310929

Adjacent sequences: A257895 A257896 A257897 * A257899 A257900 A257901

Keyword

nonn,cons

Author

Iaroslav V. Blagouchine, May 12 2015

Status

approved