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 A157833 Numbers k such that 1 + Sum_{j=0..k} (-1)^j*(k-j)! 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 k is even, 3 divides the sum. The sums corresponding to terms >= 661 are only probable primes. - Klaus Brockhaus, Mar 13 2009 LINKS Table of n, a(n) for n=1..15. 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 A335203 Adjacent sequences: A157830 A157831 A157832 * A157834 A157835 A157836 KEYWORD nonn,more 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 September 29 02:18 EDT 2023. Contains 365748 sequences. (Running on oeis4.)