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%I #23 Oct 18 2023 09:58:59
%S 3,107,3821,79559,1260989,18409199,252427601,3285916169,41375648687,
%T 507575862527,6100479510551
%N a(n) = (10^n)-th lower twin prime.
%C 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.
%C 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
%H Cino Hilliard, <a href="http://groups.google.com/group/sumprimes/web/sumtwinsfirstn-c">Approximating the n-th lower twin prime</a> (broken link)
%F a(n) = A001359(10^n). - _M. F. Hasler_, Dec 06 2008
%e 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.
%Y Cf. A001097, A001359, A147797.
%K nonn,more
%O 0,1
%A _Cino Hilliard_, Oct 28 2008
%E a(0) from _Zak Seidov_, Oct 29 2008
%E Edited and cross-references added by _M. F. Hasler_, Dec 06 2008