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
Keywords
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
Programs
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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