|
| |
|
|
A066856
|
|
Omega(n!+1), where omega is the number of distinct primes dividing n, A001221.
|
|
4
| |
|
|
1, 1, 1, 1, 1, 2, 1, 2, 3, 2, 1, 2, 2, 2, 3, 5, 3, 6, 2, 2, 3, 3, 3, 2, 2, 2, 1, 2, 3, 5, 4, 4, 5, 2, 5, 6, 1, 2, 4, 7, 1, 3, 4, 3, 3, 3, 4, 2, 5, 5, 6, 4, 4, 2, 2, 4, 3, 4, 2, 4, 4, 3, 5, 3, 4, 5, 4, 5, 6, 5, 2, 7, 1, 4, 2, 3, 1, 6, 3, 4, 7, 3, 3, 3, 5, 5, 4, 3, 8, 3, 6, 2, 4, 3, 4, 5, 6, 6, 5, 5, 4, 5
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,6
|
|
|
COMMENTS
| 103!+1 = 27437*31084943*C153, so a(103) is unknown until this 153-digit composite is factored. a(104) = 4 and a(105) = 6. - Rick L. Shepherd (rshepherd2(AT)hotmail.com), Jun 09 2003
|
|
|
LINKS
| Hisanori Mishima, Appendix 1. Factorization results for n!+1
Paul Leyland, Factors of n!+1 [Typo in URL corrected by R. J. Mathar, Nov 21 2008]
Hisanori Mishima, Bernoulli numbers (n = 2 to 114)
|
|
|
MATHEMATICA
| Table[ Length[ FactorInteger[ n! + 1]], {n, 1, 15}]
|
|
|
PROG
| (PARI) for(n=1, 64, print1(omega(n!+1), ", "))
|
|
|
CROSSREFS
| Cf. A054990 (bigomega(n!+1)), A002981 (n!+1 is prime), A064237 (n!+1 divisible by a square), A084846 (mu(n!+1)).
Sequence in context: A059131 A059129 A081771 * A089280 A192099 A193101
Adjacent sequences: A066853 A066854 A066855 * A066857 A066858 A066859
|
|
|
KEYWORD
| hard,nonn
|
|
|
AUTHOR
| Robert G. Wilson v (rgwv(AT)rgwv.com), Jan 21 2002
|
|
|
EXTENSIONS
| More terms from Rick L. Shepherd (rshepherd2(AT)hotmail.com), Jun 09 2003
|
| |
|
|
