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A154668
Averages of twin primes such that p1*p2 -+ AverageTwinPrime are primes.
1
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
1,1
LINKS
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
KEYWORD
nonn
AUTHOR
STATUS
approved