A163385 Primes p such that 3(p-3)-1 and 3(p-3)+1 are twin primes.
5, 7, 13, 17, 23, 37, 53, 67, 79, 83, 97, 107, 157, 193, 223, 277, 347, 353, 367, 433, 443, 479, 487, 499, 569, 577, 599, 647, 653, 773, 797, 853, 907, 937, 1087, 1103, 1123, 1259, 1277, 1367, 1409, 1423, 1427, 1549, 1553, 1747, 1889, 2069, 2153, 2237, 2267
Offset: 1
Examples
3*(5-3) = 6, 3*(7-3) = 12, 3*(13-3) = 30, ...
Links
- Robert Israel, Table of n, a(n) for n = 1..10000
Crossrefs
Programs
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Maple
select(p -> isprime(p) and isprime(3*p-10) and isprime(3*p-8), [seq(i,i=3..10000,2)]); # Robert Israel, Nov 13 2016
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Mathematica
f1[n_]:=If[PrimeQ[n-1]&&PrimeQ[n+1],True,False]; f2[n_]:=If[f1[n]&&PrimeQ[n/3+3],True,False]; lst={};Do[If[f2[n],AppendTo[lst,n/3+3]],{n,8!}];lst Select[Prime[Range[400]],AllTrue[3(#-3)+{1,-1},PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Jan 16 2017 *)
Extensions
Definition clarified and edited by Omar E. Pol, Aug 05 2009
Comments