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A092927 Smallest prime of the form n(n-1)(n-2)...(n-k)+1, or 0 if no such prime exists. 6
2, 3, 7, 5, 61, 7, 43, 337, 73, 11, 991, 13, 157, 121080961, 211, 17, 14820309504001, 19, 0, 6841, 421, 23, 10627, 96909121, 601, 15601, 17551, 29, 173059286401, 31, 530122321, 29761, 3569119343741952001, 1123, 25622035084801, 37 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
EXAMPLE
a(8) = 8*7*6 +1 = 337.
MATHEMATICA
Flatten[Table[Select[Rest[FoldList[Times, 1, Range[n, 1, -1]]]+1, PrimeQ, 1]/. {}->{0}, {n, 40}]] (* Harvey P. Dale, Jul 10 2012 *)
PROG
(PARI) f(n, k)=prod(i=n-k, n, i)+1; a(n)=for (i=0, n, if(isprime(f(n, i)), print1(f(n, i)); break()))
CROSSREFS
Sequence in context: A353075 A069587 A059843 * A071553 A021812 A155891
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Mar 18 2004
EXTENSIONS
More terms from Mohammed Bouayoun (bouyao(AT)wanadoo.fr), Mar 19 2004
STATUS
approved

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Last modified June 18 12:25 EDT 2024. Contains 373481 sequences. (Running on oeis4.)