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Largest prime not exceeding Fibonacci(n) = A000045(n).
4

%I #22 Dec 25 2015 00:18:08

%S 2,3,5,7,13,19,31,53,89,139,233,373,607,983,1597,2579,4177,6763,10939,

%T 17707,28657,46351,75017,121379,196387,317797,514229,832003,1346249,

%U 2178283,3524569,5702867,9227443,14930341,24157811,39088157,63245971

%N Largest prime not exceeding Fibonacci(n) = A000045(n).

%H Harry J. Smith, <a href="/A138184/b138184.txt">Table of n, a(n) for n = 3..657</a>

%F a(n) = A000040(A054782(n)). - _R. J. Mathar_, Apr 22 2008

%e a(8) = 19 because 19 is the largest prime not exceeding 21 = A000045(8).

%p A138184 := proc(n) prevprime(combinat[fibonacci](n)+1) ; end: seq(A138184(n),n=3..45) ; # _R. J. Mathar_, Apr 22 2008

%t PrimePrev[n_]:=Module[{k=n},While[ !PrimeQ[k],k-- ];k];f[n_]:=Fibonacci[n];lst={};Do[AppendTo[lst,PrimePrev[f[n]]],{n,5!}];lst (* _Vladimir Joseph Stephan Orlovsky_, Feb 26 2010 *)

%Y Cf. A138181, A138182, A138183, A138185.

%K easy,nonn

%O 3,1

%A _Colm Mulcahy_, Mar 04 2008

%E Edited and extended by _R. J. Mathar_, Apr 22 2008

%E Offset changed from 4 to 3 by _Harry J. Smith_, Jan 02 2009