A216574 - OEIS

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A216574

Numbers n such that the n-th Fibonacci number is prime, but cannot be written in the form a^2 + 10*b^2.

3, 4, 5, 7, 13, 17, 23, 29, 43, 47, 83, 137, 433, 449, 509, 569, 571, 2971, 4723, 5387, 9677, 14431, 30757, 50833, 104911, 201107, 433781, 604711, 931517, 1049897, 1285607, 1636007

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..32.

Blair Kelly, Factorizations of Fibonacci and Lucas numbers

CROSSREFS

Cf. A000045, A001605.

Sequence in context: A079463 A325422 A190213 * A216561 A192269 A284618

Adjacent sequences: A216571 A216572 A216573 * A216575 A216576 A216577

KEYWORD

nonn

AUTHOR

V. Raman, Sep 08 2012

STATUS

approved