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A256003 a(n) = 0 followed by numerators of 2*A176327(n)/A176289(n). 0
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 (list; graph; refs; listen; history; text; internal format)
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
FORMULA
a(2n) = 0. a(2n+1) = A172086(2n), from the main pure Bernoulli twin numbers.
CROSSREFS
Sequence in context: A117145 A338822 A083912 * A157187 A152140 A292252
KEYWORD
sign,frac
AUTHOR
Paul Curtz, May 06 2015
STATUS
approved

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Last modified May 24 00:44 EDT 2024. Contains 372765 sequences. (Running on oeis4.)