login
Primes p such that p, p+42, p+84 are consecutive primes.
8

%I #21 May 30 2018 03:55:35

%S 247099,689467,1008617,1629767,1658627,2024647,2750999,2811719,

%T 2880907,2921777,3264449,3295027,3311317,3365449,3555269,3668419,

%U 4059229,4412099,4440529,4549309,4619357,4690219,4802947,4955179,5115259

%N Primes p such that p, p+42, p+84 are consecutive primes.

%C Old name was: Primes p(k) such that p(k+2)-p(k+1)=p(k+1)-p(k)=42.

%H Zak Seidov, <a href="/A052198/b052198.txt">Table of n, a(n) for n = 1..2000</a>

%t Select[Partition[Prime[Range[400000]],3,1],Differences[#]=={42,42}&][[All,1]] (* _Harvey P. Dale_, May 28 2017 *)

%o (PARI) is_A052198(n)=nextprime(n+1)==n+42 && nextprime(n+43)==n+84 && isprime(n) \\ _Charles R Greathouse IV_, Jan 07 2013, typo corrected by _M. F. Hasler_, Jan 13 2013

%Y Cf. A001223, A033451, A047948, A052197.

%K nonn

%O 1,1

%A _Labos Elemer_, Jan 28 2000

%E New name from _Charles R Greathouse IV_, Jan 07 2013