|
| |
|
|
A114362
|
|
Numerator of zeta(4n)/zeta(2n)^2 (with a(0)=2 instead of -2).
|
|
1
| |
|
|
2, 2, 6, 691, 7234, 523833, 3545461365, 3392780147, 15418642082434, 26315271553053477373, 261082718496449122051, 2530297234481911294093, 39265823582984723803743892829, 61628132164268458257532691681
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,1
|
|
|
COMMENTS
| zeta(4n)/zeta(2n)^2 is a rational value expressible in term of Bernoulli's numbers (A027641).
|
|
|
FORMULA
| prod( (p^{2n}-1)/(p^{2n}+1)=zeta(4n)/zeta(2n)^2 where the product is over all the primes
|
|
|
PROG
| (PARI) z(n)=bernfrac(2*n)*(-1)^(n - 1)*2^(2*n-1)/(2*n)!; a(n)=if(n<1, 2, numerator(z(2*n)/z(n)^2))
|
|
|
CROSSREFS
| Cf. A027641, A114363.
Sequence in context: A184712 A181265 A093909 * A164325 A198880 A201315
Adjacent sequences: A114359 A114360 A114361 * A114363 A114364 A114365
|
|
|
KEYWORD
| frac,nonn
|
|
|
AUTHOR
| Benoit Cloitre (benoit7848c(AT)orange.fr), Feb 09 2006; corrected Feb 22 2006
|
| |
|
|
