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A206762 a(n) is the least number from 1,2,...,n-1, such that n!/a(n)+1 is prime, and a(n)=0, if such number does not exist. 0
1, 1, 2, 2, 3, 2, 2, 5, 6, 1, 8, 2, 5, 7, 2, 3, 0, 5, 8, 4, 16, 3, 8, 4, 10, 1, 13, 8, 2, 19, 4, 11, 11, 7, 3, 1, 12, 13, 4, 1, 24, 2, 8, 5, 9, 25, 16, 2, 12, 0, 26, 0, 17, 22, 44, 22, 37, 7, 48, 4, 37, 18, 7, 39, 16, 19, 7, 15, 19, 36, 30, 1, 14, 15, 16, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,3

COMMENTS

The sequence of primes n!/a(n)+1, when a(n)>0, is increasing.

LINKS

Table of n, a(n) for n=2..77.

MATHEMATICA

Table[s = Select[Range[n - 1], PrimeQ[n!/# + 1] &, 1]; If[s == {}, 0, s[[1]]], {n, 2, 100}] (* T. D. Noe, Feb 13 2012 *)

CROSSREFS

Cf. A089136, A092265, A092965, A092969, A092970.

Sequence in context: A210967 A343534 A275383 * A212281 A225637 A185268

Adjacent sequences:  A206759 A206760 A206761 * A206763 A206764 A206765

KEYWORD

nonn

AUTHOR

Vladimir Shevelev, Feb 12 2012

STATUS

approved

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Last modified September 17 19:02 EDT 2021. Contains 347489 sequences. (Running on oeis4.)