login
This site is supported by donations to The OEIS Foundation.

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A049432 Numbers n such that n!-(n-1)!+1 is prime. 5
2, 3, 4, 5, 6, 8, 13, 20, 24, 46, 59, 150, 152, 198, 683, 880, 1135, 1907, 6617, 10243 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(21) > 12000. [From Donovan Johnson, Dec 18 2009]

LINKS

Table of n, a(n) for n=1..20.

Index entries for sequences related to factorial numbers

EXAMPLE

6!-(6-1)!+1 = 601 is prime.

CROSSREFS

Cf. A049984, A049433.

Sequence in context: A133430 A033071 A306075 * A102516 A156981 A271949

Adjacent sequences:  A049429 A049430 A049431 * A049433 A049434 A049435

KEYWORD

nonn

AUTHOR

Paul Jobling (paul.jobling(AT)whitecross.com)

EXTENSIONS

More terms from Farideh Firoozbakht, Jul 18 2003

a(17)-a(20) from Donovan Johnson, Dec 18 2009

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 December 7 00:16 EST 2019. Contains 329812 sequences. (Running on oeis4.)