A000882 Number of twin prime pairs <= product of first n primes.

0, 1, 4, 15, 69, 468, 4636, 57453, 896062, 18463713, 425177757, 11997649372, 385088898632, 13280323588034, 509456736126003

Offset

1,3

Links

Table of n, a(n) for n=1..15.

Tomás Oliveira e Silva, Tables of values of pi(x) and of pi2(x) [From Donovan Johnson, Mar 01 2010]

Crossrefs

Cf. A002110, A000849.

Sequence in context: A125062 A039625 A020020 * A364908 A098614 A367040

Adjacent sequences: A000879 A000880 A000881 * A000883 A000884 A000885

Keyword

nonn,more,hard

Author

gandalf(AT)hrn.office.ssi.net (James D. Ausfahl)

Extensions

More terms from David W. Wilson

a(10)-a(15) from Donovan Johnson, Mar 01 2010

Status

approved