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A118841 Numbers n such that ceiling(phi^n) is prime. 1
1, 2, 3, 4, 8, 16 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(7) if it exists is greater than 250000. - Mark Rodenkirch, Feb 22 2020

LINKS

Table of n, a(n) for n=1..6.

Eric Weisstein's World of Mathematics, Phi-Prime

PROG

(PARI) c(n) = 3*fibonacci(n-1) + fibonacci(n-2) + (n % 2); \\ A169986(n) for n >= 1

for(n=1, 10^7, if(ispseudoprime(c(n)), print1(n, ", ")))

\\ Joerg Arndt, Feb 22 2020

CROSSREFS

Cf. A118842, A001606.

Sequence in context: A122774 A274166 A189740 * A126294 A224912 A162724

Adjacent sequences:  A118838 A118839 A118840 * A118842 A118843 A118844

KEYWORD

nonn

AUTHOR

Eric W. Weisstein, May 01 2006

EXTENSIONS

a(7)-a(8) from Charles R Greathouse IV, Jul 30 2011

a(9)-a(11) from Charles R Greathouse IV, Aug 01 2011

Incorrect a(7)-a(11) removed by Mark Rodenkirch, Feb 22 2020

STATUS

approved

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Last modified April 8 21:44 EDT 2020. Contains 333329 sequences. (Running on oeis4.)