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A036971 Numbers k such that the k-th Fibonacci number reversed is prime. 3
3, 4, 5, 7, 9, 14, 17, 21, 25, 26, 65, 98, 175, 191, 382, 497, 653, 1577, 1942, 1958, 2405, 4246, 4878, 5367, 9142, 9318, 10921, 17833, 20433, 50373, 66571, 85098, 93699, 104075 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Numbers k such that the k-th Fibonacci number appears in A095179. - Iain Fox, Oct 28 2017

LINKS

Table of n, a(n) for n=1..34.

MAPLE

revdigs:= proc(n) local L;

L:= convert(n, base, 10);

add(L[-i]*10^(i-1), i=1..nops(L))

end proc:

select(isprime@revdigs@combinat:-fibonacci, [$1..10000]); # Robert Israel, Oct 29 2017

MATHEMATICA

a = Table[FromDigits[Reverse[IntegerDigits[Fibonacci[j]]]], {j, 10000}]; b = Select[a, PrimeQ[ # ] &]; Flatten[Table[Position[a, b[[i]]], {i, 1, Length[b]}]]

Select[Range[9400], PrimeQ[IntegerReverse[Fibonacci[#]]]&] (* The program uses the IntegerReverse function from Mathematica version 10 *) (* Harvey P. Dale, Dec 08 2015 *)

PROG

(PARI) lista(nn) = for(n=3, nn, if(ispseudoprime(eval(concat(Vecrev(Str(fibonacci(n)))))), print1(n, ", "))) \\ Iain Fox, Oct 28 2017

CROSSREFS

Cf. A036797, A036972, A095179.

Sequence in context: A067530 A259796 A082922 * A000702 A067526 A101760

Adjacent sequences: A036968 A036969 A036970 * A036972 A036973 A036974

KEYWORD

nonn,base,more

AUTHOR

G. L. Honaker, Jr., Carlos Rivera

EXTENSIONS

a(25)-a(26) from Vit Planocka (planocka(AT)mistral.cz), Feb 25 2003

Offset corrected by Arkadiusz Wesolowski, Jan 12 2012

a(27)-a(31) from Iain Fox, Oct 28 2017

a(32)-a(33) from Iain Fox, Oct 29 2017

a(34) from Iain Fox, Aug 24 2021

STATUS

approved

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Last modified December 2 23:09 EST 2022. Contains 358510 sequences. (Running on oeis4.)