Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A066856
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A066856 Omega(n!+1), where omega is the number of distinct primes dividing n, A001221. +0
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; listen)
OFFSET

1,6

COMMENT

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}]

PROGRAM

(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 this_sequence A089280 A100661 A088696

Adjacent sequences: A066853 A066854 A066855 this_sequence 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

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified December 15 00:47 EST 2009. Contains 170825 sequences.


AT&T Labs Research