%I #16 Aug 08 2015 21:56:10
%S 2,3,7,11,23,31,41,47,67,71,83,109,113,131,139,149,167,193,197,233,
%T 241,251,263,271,283,317,331,347,353,373,379,401,439,443,479,487,491,
%U 503,523,541,563,571,577,587,613,619,641,727,733,761,787,809,863,877
%N a(n) = smallest prime such that a(n) + 2n is also prime and such that a(n) > a(n-1).
%C Increasing primes p such that p + 2n is prime.
%H T. D. Noe, <a href="/A108184/b108184.txt">Table of n, a(n) for n = 0..10000</a>
%e a(0)=2 since 2+0=2 is prime; a(1)=3 since 3+2=5 is prime.
%e a(2)=7 since 7+4=11 is prime; 5 is not in the sequence since 5+4=9 is not prime.
%p A108184 := proc(n) option remember; if n = 1 then 3; else for a from procname(n-1)+1 do if isprime(a) and isprime(a+2*n) then RETURN(a) ; fi; od: fi; end: seq(A108184(n),n=1..100) ; # _R. J. Mathar_, Jan 31 2009
%t t = {2}; Do[p = NextPrime[t[[-1]]]; While[! PrimeQ[p + 2 n], p = NextPrime[p]]; AppendTo[t, p], {n, 100}]; t (* _T. D. Noe_, Feb 04 2014 *)
%o (PARI) A108184(maxp) = {my(a=[2], n=1); forprime(p=3, maxp, if(isprime(p+2*n), n++; a=concat(a, p))); a} \\ _Colin Barker_, Feb 03 2014
%Y Cf. A020483, A237055
%K easy,nonn
%O 0,1
%A _Giovanni Teofilatto_, Jun 28 2005
%E Edited and extended by _Ray Chandler_, Jul 07 2005
%E Edited by _N. J. A. Sloane_, Feb 11 2009 at the suggestion of _R. J. Mathar_