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.

A092027 Duplicate of A084750.

Original entry on oeis.org

4, 5, 10, 11, 12, 14, 29, 53, 81, 90, 116, 236, 323, 346, 1172, 2957
Offset: 1

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Author

Keywords

A084749 Numbers m such that m! + p is a prime, where p is the smallest prime > m.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 7, 10, 33, 44, 48, 52, 64, 73, 92, 119, 182, 487, 603, 987, 4884, 6822, 8070, 11079, 13659, 17659
Offset: 1

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Author

Amarnath Murthy and Meenakshi Srikanth (menakan_s(AT)yahoo.com), Jun 16 2003

Keywords

Comments

Next term, if it exists, is >4800. - Ryan Propper, Jan 02 2007
From Farideh Firoozbakht, Oct 21 2009: (Start)
Numbers corresponding to a(19)-a(24) are probable primes.
There is no further term up to 8300. (End)

Examples

			727 = 6! + 7 is a prime but 8! + 11 is composite hence 6 is a member but 8 is not.
7 is in the sequence because 7!=5040, nextprime(7)=11 and 5040+11 is prime.

Crossrefs

Cf. A084748, A084750, A092028, A064278, A002981, A151892.

Programs

  • Mathematica
    Do[If[PrimeQ[k!+NextPrime[k]], Print[k]], {k, 0, 1525}] (* Farideh Firoozbakht, Feb 26 2004 *)
Select[Range[0,500],PrimeQ[#!+NextPrime[#]]&] (* The program generates the first 19 terms of the sequence. *) (* Harvey P. Dale, Jul 16 2025 *)

Extensions

More terms from Farideh Firoozbakht, Feb 26 2004
Edited by N. J. A. Sloane at the suggestion of Artur Jasinski, Apr 14 2008
a(22)-a(24) from Farideh Firoozbakht, Oct 21 2009
a(25) from Michael S. Branicky, Aug 05 2024
a(26)-a(27) from Michael S. Branicky, May 25 2025

A084751 Primes of the form k! - p, where p is the smallest prime > k.

Original entry on oeis.org

19, 113, 3628789, 39916787, 479001587, 87178291183, 8841761993739701954543615999969, 4274883284060025564298013753389399649690343788366813724671999999999941
Offset: 1

Views

Author

Amarnath Murthy and Meenakshi Srikanth (menakan_s(AT)yahoo.com), Jun 16 2003

Keywords

Comments

The next term (a(9)) has 121 digits. - Harvey P. Dale, May 02 2015

Crossrefs

Cf. A084750.

Programs

  • Mathematica
    For[n = 1, n < 60, n++, If[PrimeQ[n! - Prime[PrimePi[n] + 1]], Print[n! - Prime[PrimePi[n] + 1]]]] (Steinerberger)
Select[Table[n!-NextPrime[n],{n,100}],PrimeQ] (* Harvey P. Dale, May 02 2015 *)

Extensions

More terms from Stefan Steinerberger, Feb 06 2006
Showing 1-3 of 3 results.

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

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