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 1-3 of 3 results.

A053408 Numbers k such that A003266(k) + 1 is prime.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 22, 28
Offset: 1

Views

Author

G. L. Honaker, Jr., Jan 08 2000

Keywords

Comments

Next term > 300. - Joerg Arndt, Aug 16 2014
The corresponding primes are given in A053413. - Joerg Arndt, Aug 17 2014
If it exists, a(11) > 1100. - Robert Price, May 27 2019

Links

Crossrefs

Cf. A000040, A000045, A003266, A053412, A053413, A059709.

Programs

  • Mathematica
    Select[Range[30], PrimeQ[Fibonorial[#] + 1] &] (* Robert Price, May 26 2019 *)
  • PARI
    ff(n)=prod(i=1, n, fibonacci(i));
for(n=1,10^6, if(ispseudoprime(ff(n)+1), print1(n,", "))); \\ Joerg Arndt, Aug 16 2014

Extensions

Definition edited by Daniel Forgues, Nov 29 2009
Edited definition, Joerg Arndt, Aug 17 2014

A053413 Primes of the form A003266(n) + 1.

Original entry on oeis.org

2, 2, 3, 7, 31, 241, 3121, 65521, 1879127177606120717127879344567470740879360001, 1419564463863171507576408104556964008024375775796704645430601388670976000001
Offset: 1

Views

Author

G. L. Honaker, Jr., Jan 09 2000

Keywords

Comments

The corresponding n are given in A053408. - Joerg Arndt, Aug 16 2014

Links

Crossrefs

Cf. A059709, A053408.

Programs

  • Mathematica
    Select[Rest[FoldList[Times,1,Fibonacci[Range[80]]]+1],PrimeQ] (* Harvey P. Dale, Apr 25 2012 *)

Extensions

Edited by Daniel Forgues, Nov 30 2009
One more term (a(10)) from Harvey P. Dale, Apr 25 2012
Edited definition, Joerg Arndt, Aug 17 2014

A336481 a(n) is the smallest positive k such that Fibonorial(n) - k is a prime, for n>3.

Original entry on oeis.org

1, 1, 1, 1, 1, 11, 19, 19, 29, 19, 1, 1, 97, 41, 23, 131, 107, 53, 101, 529, 53, 269, 347, 97, 317, 97, 353, 73, 97, 193, 71, 1543, 661, 257, 193, 191, 151, 443, 167, 967, 251, 2441, 163, 151, 379, 229, 127, 59, 1223, 911, 389, 349, 919, 179, 1051, 167, 547, 541
Offset: 4

Views

Author

Mohamed Sami Gattoufi, Jul 22 2020

Keywords

Examples

			For n=5, a(5) = Fibonorial(5) - 1 = 30 - 1 = 29 is a prime.

Crossrefs

Cf. A003266, A059709 (locations of 1's), A336480.

Programs

  • Mathematica
    Table[(Fibonorial[n]-NextPrime[Fibonorial[n],-1]),{n,4,50}]
  • PARI
    f(n) = prod(i=1, n, fibonacci(i)); \\ A003266
a(n) = my(fn=f(n)); fn - precprime(fn-1); \\ Michel Marcus, Jul 23 2020
Showing 1-3 of 3 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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