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A240715 Primes p such that p*q*r + 6 and p*q*r - 6 are primes where q and r are the next two primes after p. 2
569, 1531, 1549, 7103, 7451, 9013, 10627, 10853, 11779, 11783, 12671, 12941, 14821, 14851, 17489, 18493, 20717, 20959, 25237, 26309, 27739, 29669, 29873, 34549, 35977, 36251, 37591, 38351, 38639, 39551, 40129, 45589, 46957, 47317, 48781, 55163, 55259 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

K. D. Bajpai, Table of n, a(n) for n = 1..1444

EXAMPLE

569 is in the sequence because 569*571*577 + 6 = 187466729 and 569*571*577 - 6 = 187466717 are both prime where 571 and 577 are the next two primes after 569.

1531 is in the sequence because 1531*1543*1549 + 6 = 3659253823 and 1531*1543*1549 - 6 = 3659253811 are both prime where 1543 and 1549 are the next two primes after 1531.

MAPLE

KD := proc(n) local a, b, d; a:=ithprime(n)*ithprime(n+1)*ithprime(n+2); b:=a+6; d:=a-6; if  isprime(b) and isprime(d) then RETURN (ithprime(n)); fi; end: seq(KD(n), n=1..10000);

MATHEMATICA

c = 0; Do[If[PrimeQ[Prime[n]*Prime[n+1]*Prime[n+2] +6] && PrimeQ[Prime[n]*Prime[n+1]*Prime[n+2] -6], c=c+1; Print[c, " ", Prime[n]]], {n, 1, 500000}];

KD={};   f=Prime[n+1]*Prime[n+2];  Do[p=Prime[n]; If[ PrimeQ[p*f+6] && PrimeQ[p*f-6], AppendTo[KD, p]], {n, 10000}]; KD

PROG

(Magma) [p: p in PrimesUpTo(10^5) | IsPrime(t-6) and IsPrime(t+6) where t is p*NextPrime(p)*NextPrime(NextPrime(p))]; // Bruno Berselli, Apr 11 2014

CROSSREFS

Cf. A006094, A048880, A051507, A240596.

Sequence in context: A356443 A142818 A103818 * A263708 A219992 A221218

Adjacent sequences:  A240712 A240713 A240714 * A240716 A240717 A240718

KEYWORD

nonn

AUTHOR

K. D. Bajpai, Apr 10 2014

STATUS

approved

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Last modified October 1 23:34 EDT 2022. Contains 357173 sequences. (Running on oeis4.)