

A146214


a(n) = (10^n)th lower twin prime.


3



3, 107, 3821, 79559, 1260989, 18409199, 252427601, 3285916169, 41375648687, 507575862527, 6100479510551
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OFFSET

0,1


COMMENTS

The Gcc with Gmp program is at the bottom of the link. The link also has a PARI bisection algorithm which gives a very good approximation for the nth prime number and the nth twin prime number. For example the 10^10th lower twin prime approximation is 6100475249386, this has a relative error of 0.000000698... from the actual a(10) above.
The (10^n)th upper twin prime is given as a(n)+2 = (5,109,3823,79561, 1260991,18409201,252427603,...).  M. F. Hasler, Dec 06 2008


LINKS

Table of n, a(n) for n=0..10.
Cino Hilliard, Approximating the nth lower twin prime (broken link)


FORMULA

a(n) = A001359(10^n).  M. F. Hasler, Dec 06 2008


EXAMPLE

The first 10 lower twin primes are: 3,5,11,17,29,41,59,71,101,107. So 107 is the 10th lower twin prime.


CROSSREFS

Cf. A001097, A147797.
Sequence in context: A023325 A094200 A003705 * A261997 A061308 A302060
Adjacent sequences: A146211 A146212 A146213 * A146215 A146216 A146217


KEYWORD

nonn,more


AUTHOR

Cino Hilliard, Oct 28 2008


EXTENSIONS

a(0) from Zak Seidov, Oct 29 2008
Edited and crossreferences added by M. F. Hasler, Dec 06 2008


STATUS

approved



