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 A176049 Primes of the form n!*(n+1)!*(n+2)! - 1 or n!*(n+1)!*(n+2)! + 1. 0
 3, 11, 13, 2073601, 146313215999, 52563198423859200001, 709885457731229765106401279999999, 15120395453651827088974983182763034097693491200000000001 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Primes of the form A010790(k)-1 or A010790(k)+1. This is the 3rd sequence in the supersequence whose first member is factorial primes, A002981 UNION A002982, and whose 2nd member is A176038 Primes of the form n!*(n+1)! - 1 or n!*(n+1)! + 1. a(9) has already 486 digits and is not listed for that reason. The sequence is generated by the n-values 0, 1, 1, 4, 6, 9, 13, 19, 101, 196,... [From R. J. Mathar, Oct 03 2010] a(9) also ends with 72 nines. - Harvey P. Dale, Jan 05 2013 LINKS EXAMPLE a(2) = 11 because 1!*(1+1)!*(1+2)! - 1 = 11 is prime. a(4) = 2073601 because 4!*(4+1)!*(4+2)! + 1 = 2073601 is prime. a(7) because 13!*(13+1)!*(13+2)! - 1 = 709885457731229765106401279999999 is prime. MATHEMATICA Select[Union[Flatten[Times@@#+{1, -1}&/@Partition[Range[0, 30]!, 3, 1]]], PrimeQ] (* Harvey P. Dale, Jan 05 2013 *) CROSSREFS Cf. A000040, A000142, A002981, A002982, A010790, A176038. Sequence in context: A105290 A201426 A158790 * A228237 A186078 A224857 Adjacent sequences:  A176046 A176047 A176048 * A176050 A176051 A176052 KEYWORD easy,nonn AUTHOR Jonathan Vos Post, Apr 07 2010 EXTENSIONS a(8) from R. J. Mathar, Oct 03 2010 STATUS approved

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Last modified January 27 12:01 EST 2020. Contains 331295 sequences. (Running on oeis4.)