A216560 Numbers n such that the n-th Fibonacci number is prime, but cannot be written in the form a^2 + 2*b^2.

5, 7, 17, 29, 43, 137, 449, 509, 569, 571, 2971, 4723, 9677, 14431, 104911, 433781, 604711, 931517, 1049897

Offset

1,1

Links

Table of n, a(n) for n=1..19.

Blair Kelly, Factorizations of Fibonacci and Lucas numbers

Crossrefs

Cf. A000045, A001605.

Sequence in context: A114970 A048710 A126142 * A019340 A290471 A261792

Adjacent sequences: A216557 A216558 A216559 * A216561 A216562 A216563

Keyword

nonn

Author

V. Raman, Sep 08 2012

Status

approved