A033843 - OEIS

A033843

Number of twin primes < 2^n.

0, 1, 2, 3, 5, 7, 10, 17, 24, 36, 62, 107, 177, 290, 505, 860, 1526, 2679, 4750, 8535, 15500, 27995, 50638, 92246, 168617, 309561, 571313, 1056281, 1961080, 3650557, 6810670, 12739574, 23878645, 44849427, 84384508, 159082253, 300424743, 568237005, 1076431099, 2042054332, 3879202049

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OFFSET

1,3

COMMENTS

For n=2 only the lower member of the pair [3,5] is < 2^n. - Hugo Pfoertner, Feb 07 2024

LINKS

Table of n, a(n) for n=1..41.

Index entries for sequences related to numbers of primes in various ranges

CROSSREFS

Cf. A007053, A007508.

Partial sums of A095017.

Sequence in context: A182521 A283809 A104622 * A075657 A039711 A194261