Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".
Table of n, a(n) for n=0..17.
(PARI) a(n)=(-1)^(n+1)*bernfrac(2*n)*prod(p=1, 2*n+1, if(isprime(p), p, 1))
Sequence in context: A158969 A083842 A164372 * A057177 A211769 A265031
Adjacent sequences: A123533 A123534 A123535 * A123537 A123538 A123539
Benoit Cloitre, Nov 11 2006