A000885 Number of twin prime pairs < square of n-th prime.

0, 2, 4, 6, 10, 12, 19, 21, 25, 33, 35, 46, 53, 56, 67, 80, 93, 98, 117, 128, 131, 146, 160, 174, 195, 210, 217, 227, 233, 244, 286, 298, 325, 331, 376, 386, 406, 423, 444, 467, 492, 505, 554, 561, 581, 589, 641, 700, 723, 732, 748, 780, 789, 835, 868, 895, 938, 945, 975

Offset

1,2

Links

Donovan Johnson, Table of n, a(n) for n = 1..10000

Mathematica

With[{tpps=Select[Partition[Prime[Range[10000]], 2, 1], Last[#]- First[#] == 2&]}, Table[ Count[tpps, _?(Last[#]<Prime[n]^2&)], {n, 60}]] (* Harvey P. Dale, Aug 11 2011 *)

Crossrefs

Cf. A000879.

Sequence in context: A083887 A339736 A064374 * A068336 A293821 A194944

Adjacent sequences: A000882 A000883 A000884 * A000886 A000887 A000888

Keyword

nonn

Author

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

Extensions

More terms from David W. Wilson

Status

approved