|
Search: id:A118813
|
|
|
| A118813 |
|
Primes of the form (2n)! - n! - 1. |
|
+0
1
|
|
| 3628679, 87178286159, 20922789847679, 265252859812191058635000805631999
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
The next term is too large to include.
All the numbers end in 9
|
|
EXAMPLE
|
n=5 (2*5)! - 5! - 1 = 3628800 - 120 - 1 = 3628679
|
|
MAPLE
|
PFACT:=proc(N) local i, r; for i from 1 by 1 to N do r:=(2*i)!-i!-1; if isprime(r) then print(i); fi; od; end: PFACT(100);
|
|
CROSSREFS
|
Sequence in context: A107349 A053078 A116221 this_sequence A127229 A068158 A011521
Adjacent sequences: A118810 A118811 A118812 this_sequence A118814 A118815 A118816
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Paolo P. Lava and Giorgio Balzarotti (ppl(AT)spl.at), May 23 2006
|
|
|
Search completed in 0.002 seconds
|
