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A079140 Numbers n such that (Product of first n twin prime pair averages [A014574] ) - 1 is prime. 0
1, 2, 7, 11, 16, 32, 402 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Some of the larger entries may only correspond to probable primes.

LINKS

Table of n, a(n) for n=1..7.

EXAMPLE

a(2)=2 because the product of the first two terms of A014574 - 1, 4*6-1 = 23, is prime.

PROG

(PARI) {atm(N)=local(t, c); t=1; c=0; forprime(p=2, N, if(isprime(p+2), t*=p+1; c++; if(isprime(t-1), print1(c" "))))

CROSSREFS

Cf. A014574.

Sequence in context: A190518 A190750 A049635 * A176897 A166005 A243009

Adjacent sequences:  A079137 A079138 A079139 * A079141 A079142 A079143

KEYWORD

more,nonn

AUTHOR

Jason Earls, Dec 26 2002

STATUS

approved

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Last modified February 19 06:46 EST 2018. Contains 299330 sequences. (Running on oeis4.)