A036971 Numbers k such that the k-th Fibonacci number reversed is prime.

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

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