OFFSET
1,2
COMMENTS
Numbers k such that either k^2+k+1 or k^2+k+11 is prime, but not both. - R. J. Mathar, Mar 01 2010
EXAMPLE
0 is in the sequence because 0^2+0+1 = 1 is nonprime and 0^2+0+11 = 11 is prime; 1 is not in the sequence because 1^2+1+1 = 3 is prime and 1^2+1+11 = 13 is also prime, 10 is not in the sequence because 10^2+10+1 = 111 is nonprime and 10^2+10+11 = 121 is also nonprime; 14 is in the sequence because 14^2+14+1 = 211 is prime and 14^2+14+11 = 221 is nonprime.
PROG
(Magma) [ n: n in [0..130] | IsPrime(k+1) ne IsPrime(k+11) where k is n^2+n ]; // Klaus Brockhaus, Feb 26 2010
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Feb 23 2010
EXTENSIONS
Edited and extended by Klaus Brockhaus, Feb 26 2010
More terms from R. J. Mathar, Mar 01 2010
STATUS
approved