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A133320 Numbers n such that both A124296(n) = 5*F(n)^2 - 5*F(n) + 1 and A124297(n) = 5*F(n)^2 + 5*F(n) + 1 are prime, where F(n) = Fibonacci[n]. 0
3, 4, 5, 10, 40 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..5.

MATHEMATICA

Do[ F=Fibonacci[n]; f=5*F^2-5*F+1; g=5*F^2+5*F+1; If[ PrimeQ[f], If[ PrimeQ[g], Print[ {n, f, g} ] ] ], {n, 1, 1000} ]

CROSSREFS

Cf. A124297 = 5*F(n)^2 + 5*F(n) + 1, where F(n) = Fibonacci[n]. Cf. A124296 = 5*F(n)^2 - 5*F(n) + 1, where F(n) = Fibonacci[n]. Cf. A000032, A000045, A121171, A001946.

Sequence in context: A136366 A123820 A261903 * A225906 A329524 A319067

Adjacent sequences:  A133317 A133318 A133319 * A133321 A133322 A133323

KEYWORD

more,nonn

AUTHOR

Alexander Adamchuk, Oct 18 2007

STATUS

approved

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Last modified February 18 04:48 EST 2020. Contains 332011 sequences. (Running on oeis4.)