A082689 Numerator of n*sum(k=1,(-1)^(k+1)/(n+k)).

1, 1, 13, 43, 347, 1013, 36331, 20431, 973993, 5386001, 15273079, 104604613, 1495109359, 1357580423, 113225690813, 2150797323119, 6214827398881, 1922198200679, 206285491870477, 64286037044903, 7668497434066577

Offset

1,3

Links

Table of n, a(n) for n=1..21.

Formula

limit n->infinity n*sum(k=1, (-1)^(k+1)/(n+k)) = 1/4

Crossrefs

Cf. A082690 (denominators).

Sequence in context: A063650 A220612 A144236 * A228505 A224102 A123294

Adjacent sequences: A082686 A082687 A082688 * A082690 A082691 A082692

Keyword

frac,nonn

Author

Benoit Cloitre, Apr 12 2003

Status

approved