OFFSET
1,2
EXAMPLE
n=6: 2*6+1 = 13 = 2+11 = 5+8 = 6+7 and
prime(1717)=14657, prime(636)=4721, prime(516)=3697,
a(6) = #{14657=2^4+11^4, 4721=5^4+8^4, 3697=6^4+7^4} = 3.
CROSSREFS
KEYWORD
dead
AUTHOR
Reinhard Zumkeller, Mar 08 2006
STATUS
approved