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A180422 Largest prime immediately preceding a Fibonacci number. 4
2, 3, 7, 11, 19, 31, 53, 83, 139, 229, 373, 607, 983, 1583, 2579, 4177, 6763, 10939, 17707, 28649, 46351, 75017, 121379, 196387, 317797, 514219, 832003, 1346249, 2178283, 3524569, 5702867, 9227443, 14930341, 24157811, 39088157, 63245971 (list; graph; refs; listen; history; text; internal format)
OFFSET

4,1

COMMENTS

Limit ratio of two consecutive elements of this sequence is phi=1.61803... the golden ratio.

LINKS

Harvey P. Dale, Table of n, a(n) for n = 4..1000

EXAMPLE

a(7)=53 that is the prime number preceding 55=fib(10).

fib(1)=1, fib(2)=1 and fib(3)=2 are not accounted.

MATHEMATICA

NextPrime[#, -1]&/@Fibonacci[Range[4, 40]] (* Harvey P. Dale, Oct 31 2013 *)

PROG

(PARI) a(n)=precprime(fibonacci(n)-1)

CROSSREFS

Cf. A138184, A000045

Sequence in context: A210394 A211203 A158709 * A055502 A003173 A159262

Adjacent sequences:  A180419 A180420 A180421 * A180423 A180424 A180425

KEYWORD

nonn

AUTHOR

Carmine Suriano, Sep 03 2010

EXTENSIONS

Program and cross-ref from Charles R Greathouse IV, Sep 08 2010

STATUS

approved

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Last modified May 28 16:16 EDT 2017. Contains 287241 sequences.