login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A238265 Primes p such that p + 1 or p - 1 is in A055462. 1
2, 3, 23, 6911, 238878721, 5944066965503999 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Primes which are within 1 of a superduperfactorial number.

Supersequence of A193430.

LINKS

Table of n, a(n) for n=1..6.

FORMULA

a(n) are the prime values of 1! * (1! * 2!) * (1! * 2! * 3!) * (1! * 2! * 3! * n!) +/- 1.

EXAMPLE

A000142(2)^3*A000142(3)^2*A000142(4) - 1 = 6911, which is prime.

PROG

(PARI) t=1; p=1; for(n=1, 6, t*=n!; p*=t; if(isprime(p-1), print1(p-1, ", ")); if(isprime(p+1), print1(p+1, ", ")));

CROSSREFS

Cf. A000142, A055462.

Sequence in context: A092388 A225726 A076530 * A203015 A260420 A241661

Adjacent sequences:  A238262 A238263 A238264 * A238266 A238267 A238268

KEYWORD

nonn,hard

AUTHOR

Arkadiusz Wesolowski, Feb 21 2014

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 9 11:08 EDT 2020. Contains 336323 sequences. (Running on oeis4.)