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 A157833 Numbers n such that 1 + sum_{k=0..n} (-1)^k*(n-k)! is prime. 0
 2, 3, 5, 7, 15, 19, 41, 59, 61, 105, 661, 2653, 3069, 3943, 4053 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Note that when n is even, 3 divides the sum. The sums corresponding to terms >= 661 are only probable primes. - Klaus Brockhaus, Mar 13 2009 LINKS EXAMPLE a(2)=((-1)^0)(2-0)!+((-1)^1)(2-1)!+((-1)^2)(2-2)!+1=2!-1!+0!+1= 3 (prime). CROSSREFS Sequence in context: A303875 A331037 A228652 * A175758 A151531 A079987 Adjacent sequences:  A157830 A157831 A157832 * A157834 A157835 A157836 KEYWORD nonn AUTHOR Kyle D. Balliet, Mar 07 2009 EXTENSIONS a(7) - a(15) from Klaus Brockhaus, Mar 13 2009 STATUS approved

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Last modified February 18 04:48 EST 2020. Contains 332011 sequences. (Running on oeis4.)