A176132 Lesser of twin primes p0 such that 30*p0 -+ 1 and 30*p1 -+ 1 are twin primes, p1 = p0 + 2.

41, 69257, 98909, 185681, 413069, 626009, 741467, 1064951, 1096829, 1107791, 1149917, 1582811, 1819271, 1823051, 2202311, 2221379, 2748059, 3177257, 3606287, 3958457, 4275809, 4786697, 5129039, 5903897, 6533981, 6541079

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..100 from Harvey P. Dale)

Example

41 is a term since (41, 43) are twin primes, 30*41 - 1 = 1229 and 30*41 + 1=1231 are twin primes, and 30*43 - 1 = 1289 and 30*43 + 1 = 1291 are twin primes.

Mathematica

lst={}; Do[p0=Prime[n]; p1=Prime[n+1]; If[p1-p0==2&&PrimeQ[p2=p0*30-1]&&PrimeQ[p3=p0*30+1]&&PrimeQ[p4=p1*30-1]&&PrimeQ[p5=p1*30+1], AppendTo[lst, p0]], {n, 5*9!}]; lst
ltpQ[{a_, b_}]:=b-a==2&&AllTrue[{30a+1, 30a-1, 30b+1, 30b-1}, PrimeQ]; Select[ Partition[ Prime[Range[450000]], 2, 1], ltpQ][[All, 1]] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Jul 27 2019 *)

Crossrefs

Cf. A000040, A001359, A006512, A176131.

Sequence in context: A206358 A222923 A262787 * A214163 A185539 A214184

Adjacent sequences: A176129 A176130 A176131 * A176133 A176134 A176135

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Apr 09 2010

Status

approved