login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A163212
Wilson quotients (A007619) which are primes.
5
5, 103, 329891, 10513391193507374500051862069
OFFSET
1,1
COMMENTS
a(5) = A007619(137), a(6) = A007619(216), a(7) = A007619(381).
Same as A122696 without its initial term 2. - Jonathan Sondow, May 19 2013
LINKS
Peter Luschny, Swinging Primes.
Jonathan Sondow, Lerch Quotients, Lerch Primes, Fermat-Wilson Quotients, and the Wieferich-non-Wilson Primes 2, 3, 14771, in Proceedings of CANT 2011, arXiv:1110.3113 [math.NT], 2011-2012.
Jonathan Sondow, Lerch Quotients, Lerch Primes, Fermat-Wilson Quotients, and the Wieferich-non-Wilson Primes 2, 3, 14771, Combinatorial and Additive Number Theory, CANT 2011 and 2012, Springer Proc. in Math. & Stat., vol. 101 (2014), pp. 243-255.
FORMULA
a(n) = A122696(n+1) = A007619(A225906(n)) = ((A050299(n+1)-1)!+1)/A050299(n+1). - Jonathan Sondow, May 19 2013
EXAMPLE
The quotient (720+1)/7 = 103 is a Wilson quotient and a prime, so 103 is a member.
MAPLE
# WQ defined in A163210.
A163212 := n -> select(isprime, WQ(factorial, p->1, n)):
MATHEMATICA
Select[Table[p = Prime[n]; ((p-1)!+1)/p, {n, 1, 15}], PrimeQ] (* Jean-François Alcover, Jun 28 2013 *)
PROG
(PARI) forprime(p=2, 1e4, a=((p-1)!+1)/p; if(ispseudoprime(a), print1(a, ", "))) \\ Felix Fröhlich, Aug 03 2014
KEYWORD
nonn,more
AUTHOR
Peter Luschny, Jul 24 2009
STATUS
approved