|
| |
|
|
A088054
|
|
Factorial primes: primes which are within 1 of a factorial number.
|
|
3
| |
|
|
2, 3, 5, 7, 23, 719, 5039, 39916801, 479001599, 87178291199, 10888869450418352160768000001, 265252859812191058636308479999999, 263130836933693530167218012159999999, 8683317618811886495518194401279999999
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
COMMENTS
| Conjecture: 3 is the intersection of A002981 and A002982).
|
|
|
LINKS
| Wikipedia, Factorial prime.
C. Caldwell's The Top Twenty, Factorial Primes.
|
|
|
EXAMPLE
| 3!+1=7; 7!-1=5039
39916801 is a term because 11!+1 is prime.
|
|
|
MATHEMATICA
| t = {}; Do[ If[PrimeQ[n! - 1], AppendTo[t, n! - 1]]; If[PrimeQ[n! + 1], AppendTo[t, n! + 1]], {n, 50}]; t (* Robert G. Wilson v *)
Union[Select[Range[50]!-1, PrimeQ], Select[Range[50]!+1, PrimeQ]] (Noe)
fp[n_] := Module[{nf=n!}, Select[{nf-1, nf+1}, PrimeQ]]; Flatten[Table[fp[i], {i, 50}]] [From Harvey P. Dale, Dec. 18, 2010]
|
|
|
CROSSREFS
| Cf. A000142, A002981, A002982.
Union of A055490 and A088332.
Sequence in context: A062088 A070029 A110094 * A085907 A024777 A002957
Adjacent sequences: A088051 A088052 A088053 * A088055 A088056 A088057
|
|
|
KEYWORD
| easy,nice,nonn
|
|
|
AUTHOR
| Christopher M. Tomaszewski (cmt1288(AT)comcast.net), Nov 02 2003
|
|
|
EXTENSIONS
| Corrected by Paul Muljadi (paulmuljadi(AT)yahoo.com), Oct 11 2005
More terms from Robert G. Wilson v (rgwv(at)rgwv.com) and T. D. Noe (noe(AT)sspectra.com), Oct 12 2005
|
| |
|
|
