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A146214 a(n) = (10^n)-th lower twin prime. 3
3, 107, 3821, 79559, 1260989, 18409199, 252427601, 3285916169, 41375648687, 507575862527, 6100479510551 (list; graph; refs; listen; history; text; internal format)
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 n-th prime number and the n-th twin prime number. For example the 10^10-th 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
Cino Hilliard, Approximating the n-th lower twin prime (broken link)
FORMULA
a(n) = A001359(10^n). - M. F. Hasler, Dec 06 2008
EXAMPLE
For n=1, the first 10 lower twin primes (A001359) are: 3,5,11,17,29,41,59,71,101,107. So a(1) = 107 is the 10th lower twin prime.
CROSSREFS
Sequence in context: A023325 A094200 A003705 * A261997 A362056 A061308
KEYWORD
nonn,more
AUTHOR
Cino Hilliard, Oct 28 2008
EXTENSIONS
a(0) from Zak Seidov, Oct 29 2008
Edited and cross-references added by M. F. Hasler, Dec 06 2008
STATUS
approved

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Last modified April 17 08:05 EDT 2024. Contains 371756 sequences. (Running on oeis4.)