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A118913 Primes of the form n! + (n+1)! + 1. 7
3, 31, 45361, 3991681, 2516506653355019284889240277665777045474566836669417196965412366518489408149127168000000000000001 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The next term has 595 digits. - Harvey P. Dale, May 30 2016

LINKS

Table of n, a(n) for n=1..5.

EXAMPLE

a(2) = 3! + 4! + 1 = 6 + 24 + 1 = 31.

a(3) = 7! + 8! + 1 = 5040 + 40320 + 1 = 45361.

MAPLE

P:=proc(n) local i, j; for i from 1 by 1 to n do j:=i!+(i+1)!+1; if isprime(j) then print(j); fi; od; end: P(200);

MATHEMATICA

lst={}; Do[p=n!+(n+1)!+1; If[PrimeQ[p], AppendTo[lst, p]], {n, 0, 5!}]; lst (* Vladimir Joseph Stephan Orlovsky, Jan 27 2009 *)

Select[Total[#]+1&/@Partition[Range[0, 300]!, 2, 1], PrimeQ] (* Harvey P. Dale, May 30 2016 *)

PROG

(PARI) for(n=0, 1e3, if(isprime(k=n!+(n+1)!+1), print1(k", "))) \\ Charles R Greathouse IV, Feb 14 2011

CROSSREFS

Indices in A087147. - Dmitry Kamenetsky, Oct 21 2008

Sequence in context: A144964 A168678 A276199 * A297480 A282973 A005042

Adjacent sequences:  A118910 A118911 A118912 * A118914 A118915 A118916

KEYWORD

nonn

AUTHOR

Paolo P. Lava and Giorgio Balzarotti, May 25 2006

EXTENSIONS

First term inserted (because 0! + 1! + 1 = 3 is prime) by Dmitry Kamenetsky, Oct 21 2008

STATUS

approved

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Last modified June 24 01:22 EDT 2018. Contains 311819 sequences. (Running on oeis4.)