OFFSET
1,1
LINKS
Zak Seidov, Table of n, a(n) for n = 1..1000
EXAMPLE
7^2 + 1 = 50 = 2*5^2, 41^2 + 1 = 1681 = 2*29^2.
MATHEMATICA
Select[Prime[Range[300]], ! SquareFreeQ[#^2 + 1] &]
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Apr 16 2013
STATUS
approved