A154668 - OEIS

A154668

Averages of twin primes such that p1*p2 -+ AverageTwinPrime are primes.

4, 6, 60, 420, 2730, 8970, 11970, 21840, 28620, 29130, 44130, 48120, 55050, 56100, 61980, 74160, 84390, 87540, 111270, 111870, 143880, 176550, 191670, 207510, 227610, 229590, 233550, 251220, 258330, 281580, 324450, 343770, 356820, 390000

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OFFSET

1,1

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

EXAMPLE

3*5 - 4 = 11 and 3*5 + 4 = 19.

5*7 - 6 = 29 and 5*7 + 6 = 41.

MATHEMATICA

lst={}; Do[If[PrimeQ[n-1]&&PrimeQ[n+1], If[PrimeQ[(n-1)*(n+1)-n]&&PrimeQ[(n-1)*(n+1)+n], AppendTo[lst, n]]], {n, 2*9!}]; lst

PROG

(Magma) [NthPrime(k)+1:k in [1..35000]|IsPrime(NthPrime(k)+2) and forall{s:s in [1+NthPrime(k), -1-NthPrime(k)]|IsPrime(NthPrime(k)*NthPrime(k+1)+s)}]; // Marius A. Burtea, Dec 22 2019

CROSSREFS

Cf. A014574, A154666, A154667.

Sequence in context: A058162 A244388 A132929 * A363861 A189790 A053489

Adjacent sequences: A154665 A154666 A154667 * A154669 A154670 A154671

KEYWORD

nonn

AUTHOR

Vladimir Joseph Stephan Orlovsky, Jan 13 2009

STATUS

approved