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A174957 Lesser of twin primes p1 such that p1*p2-4 and p1*p2-6 are twin prime numbers. 1
5, 11, 1031, 2711, 3851, 4421, 5867, 8837, 10067, 12041, 12251, 12611, 17957, 21491, 21521, 22037, 22481, 23537, 32141, 32411, 42641, 48311, 48731, 49367, 50261, 53231, 60167, 72167, 77417, 80147, 80447, 81047, 87641, 88337, 90527, 95231 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

5*7=35; 35-4=31; 35-6=29; 29,31 twin primes

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

MATHEMATICA

lst={}; Do[p1=Prime[n]; p2=p1+2; If[PrimeQ[p2]&&PrimeQ[p1*p2-4]&&PrimeQ[p1*p2-6], (*Print[p1]; *)AppendTo[lst, p1]], {n, 8!}]; lst

ltp[{a_, b_}]:=b-a==2&&AllTrue[a*b-{4, 6}, PrimeQ]; Select[Partition[Prime[ Range[ 10000]], 2, 1], ltp][[All, 1]] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Dec 07 2017 *)

CROSSREFS

Cf. A001359, A174913, A174915, A174916, A174917, A174920, A174922, A174955

Sequence in context: A056253 A101832 A046957 * A174955 A224095 A130735

Adjacent sequences: A174954 A174955 A174956 * A174958 A174959 A174960

KEYWORD

nonn

AUTHOR

Vladimir Joseph Stephan Orlovsky, Apr 02 2010

STATUS

approved

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Last modified February 5 20:57 EST 2023. Contains 360087 sequences. (Running on oeis4.)