1,2

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.

Cf. A036468, A005408.

Adjacent sequences: A115394 A115395 A115396 this_sequence A115398 A115399 A115400

Sequence in context: A119880 A075019 A138960 this_sequence A075370 A030350 A026240

nonn

Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Mar 08 2006