cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-2 of 2 results.

A036797 Iccanobif (or iccanobiF) primes: primes which are Fibonacci numbers when reversed.

Original entry on oeis.org

2, 3, 5, 31, 43, 773, 7951, 52057, 64901, 393121, 56577108676171, 940647607443258103531, 5237879497657222310489731409575442761, 9026258083384996860449366072142307801963, 19900335674812302969315720344396951060628175943800862267761734431012073266446403
Offset: 1

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Author

Keywords

Comments

The next term has 104 digits. - Harvey P. Dale, Jul 24 2013

Crossrefs

Programs

  • Mathematica
    Sort[Select[FromDigits[Reverse[IntegerDigits[#]]]&/@ Fibonacci[ Range[ 500]],PrimeQ]] (* Harvey P. Dale, Jul 24 2013 *)

Extensions

Additional term from Harvey P. Dale, Jul 24 2013

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

Original entry on oeis.org

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

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Author

Keywords

Comments

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

Crossrefs

Programs

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

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
Showing 1-2 of 2 results.