%I #3 Oct 01 2013 21:35:23
%S 17,1447,2053,34367,50383,94427,140473,154487,190523,220553,286619,
%T 4303763,4763809,6443977,8504183,9044237,11304463,13404673,15504883,
%U 17005033,18145147,18345167,19605293,21205453,22345567,22605593
%N Primes in A129910.
%t a = {51}; For[n = 3, n < 500, n++, If[Prime[n + 1] == Prime[n] + 2, AppendTo[a, FromDigits[Join[IntegerDigits[Prime[n + 1]], IntegerDigits[Prime[n]]]]]]]; Select[a/3, PrimeQ[ # ] &]
%o (PARI) concattwins3r(n) = { local(x,y); forprime(x=2,n, if(isprime(x+2), y=floor(eval(concat(Str(x+2), Str(x)))/3); print1(y",") ) ) }
%K nonn,less
%O 1,1
%A _Cino Hilliard_, Jun 05 2007
%E Edited and extended by _Stefan Steinerberger_, Aug 02 2007