A256003 a(n) = 0 followed by numerators of 2*A176327(n)/A176289(n).

0, 2, 0, 1, 0, -1, 0, 1, 0, -1, 0, 5, 0, -691, 0, 7, 0, -3617, 0, 43867, 0, -174611, 0, 854513, 0, -236364091, 0, 8553103, 0, -23749461029, 0, 8615841276005, 0, -7709321041217, 0, 2577687858367, 0, -26315271553053477373, 0

Offset

0,2

Comments

Offset 0 is chosen instead of -1. (The offset 0 corresponds to A176327(n), -1 to 0 followed by A176327(n).)

Denominators: b(n) = 1 followed by A141459(n).

Difference table of a(n)/b(n):

0, 2, 0, 1/3, 0, -1/15, 0, ...

2, -2, 1/3, -1/3, -1/15, 1/15, ...

-4, 7/3, -2/3, 4/15, 2/15, ...

19/3, -3, 14/15, -2/15, ...

-28/3, 59/15, -16/15, ...

199/15, -5, ...

-274/15, ...

etc.

Without the first column, the antidiagonal sums are (-1)^n * A254667(n+1).

The Bernoulli numbers A027641(n)/A027642(n) or A164555(n)/A027642(n) come from A000027. 0 followed by the Bernoulli numbers comes from A001477. a(0)=0 is a choice.

Links

Table of n, a(n) for n=0..38.

Formula

a(2n) = 0. a(2n+1) = A172086(2n), from the main pure Bernoulli twin numbers.

Crossrefs

Cf. A176327/A176289, A172086/A172087, A141459, A176618, A195240, A254667.

Sequence in context: A117145 A338822 A083912 * A157187 A152140 A292252

Adjacent sequences: A256000 A256001 A256002 * A256004 A256005 A256006

Keyword

sign,frac

Author

Paul Curtz, May 06 2015

Status

approved