OFFSET
1,1
COMMENTS
Not known to be infinite, but see the Matomäki link.
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
Kaisa Matomäki, A note on primes of the form p = aq^2 + 1, Acta Arith. 137 (2009), pp. 133-137.
EXAMPLE
13 is a member since 13 = 3 * 2^2 + 1 with 3 <= 2^2 and 3 is prime.
PROG
(PARI) list(lim)=my(v=List(), t); lim=lim\1-.5; forprime(p=2, sqrt(lim), for(a=1, min(lim\p^2, p^2), if(isprime(t=a*p^2+1), listput(v, t)))); vecsort(Vec(v), , 8)
CROSSREFS
KEYWORD
nonn
AUTHOR
Charles R Greathouse IV, Jun 13 2012
STATUS
approved