OFFSET
1,1
COMMENTS
From the first 10^6 primes, 6680 are terms of the sequence.
Also, all numbers k^2+1 are twice prime, and k^2+2 are thrice prime.
The number of terms less than 10^m beginning with m = 1: 0, 3, 11, 35, 160, 759, 4668, 30319, 204439, ..., .
The number of terms less than the (10^m)-th prime beginning with m = 1: 2, 7, 33, 165, 941, 6680, 48977, 373627, ..., .
LINKS
Zak Seidov, Table of n, a(n) for n = 1..6680
MATHEMATICA
fQ[n_] := PrimeQ[(n^2 + 1)/2] && PrimeQ[(n^2 + 2)/3]; Select[ Prime@ Range@ 1667, fQ] (* Robert G. Wilson v, Feb 26 2011 *)
PROG
(PARI){n=10; for(i=1, 10^4, n=nextprime(n+1); n2=n^2; if(2==bigomega(n2+1)&&2==bigomega(n2+2), print1(n, ", ")))}
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Jan 08 2011
STATUS
approved