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 A114432 Primes of the form 1 + product of the first n 4-almost primes A014613. 0

%I

%S 17,8126654054401

%N Primes of the form 1 + product of the first n 4-almost primes A014613.

%C The next term is too large to display here. - _N. J. A. Sloane_, Jul 30 2009

%C 4-almost prime analog of primorial primes A005234 (primes p such that 1 + product of primes up to p is prime) as indexed by A014545 (n such that n-th Euclid number (A006862(n)) = 1 + (Product of first n primes) is prime). In that sense, this sequence is indexed by (1, 8, ...). No more through product of first 16 of the 4-almost primes.

%C Terms are one more than the products of 4-almost primes up to 16, 81, 294, 513, 825, 1356, 1612, 2004, 2756, 7714, ... - _Charles R Greathouse IV_, Jul 28 2009

%F {a(n)} = {1 + Prod[from i = 1 to n] A014613(i)} INTERSECTION {A000040}.

%e a(1) = 17 because 1 + 16 = 1 + A014613(1) = 1 more than the first 4-almost prime is itself prime.

%e a(2) = 8126654054401 = 1 + (16 * 24 * 36 * 40 * 54 * 56 * 60 * 81) = 1 more than the product of the first 8 of the 4-almost primes and is prime.

%Y Cf. A000040, A001358, A014612, A002110, A005234, A014545, A112141.

%K nonn,bref

%O 1,1

%A _Jonathan Vos Post_, Feb 13 2006

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Last modified July 17 14:44 EDT 2019. Contains 325106 sequences. (Running on oeis4.)