A176144 a(2n) = A164555(n). a(2n+1) = A027641(n).

1, 1, 1, -1, 1, 1, 0, 0, -1, -1, 0, 0, 1, 1, 0, 0, -1, -1, 0, 0, 5, 5, 0, 0, -691, -691, 0, 0, 7, 7, 0, 0, -3617, -3617, 0, 0, 43867, 43867, 0, 0, -174611, -174611, 0, 0, 854513, 854513, 0, 0, -236364091, -236364091, 0, 0, 8553103, 8553103, 0, 0, -23749461029, -23749461029, 0, 0, 8615841276005

Offset

0,21

Comments

Formally, these are the numerators of a sequence of fractions defined by alternating A164555(n)/A027642(n) with A027641(n)/A027642(n),

which apart from the third term duplicates the Bernoulli numbers.

Essentially a duplication of the entries of A027641.

Links

Table of n, a(n) for n=0..60.

Crossrefs

Cf. A141056, A164020, A141056.

Sequence in context: A286979 A030047 A176184 * A308356 A065936 A299625

Adjacent sequences: A176141 A176142 A176143 * A176145 A176146 A176147

Keyword

sign,frac,less

Author

Paul Curtz, Apr 10 2010

Extensions

Edited by R. J. Mathar, Jun 07 2010

Status

approved