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

Offset: 1

Author

Vladimir Joseph Stephan Orlovsky, Jan 13 2009

Keywords

• nonn

Examples

			3*5 - 4 = 11 and 3*5 + 4 = 19.
5*7 - 6 = 29 and 5*7 + 6 = 41.
		

Links

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

Crossrefs

Cf. A014574, A154666, A154667.

Programs

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

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