A125502 (Product of successive primes minus 2) divided by 7 is prime.

4127, 49727, 212627, 565727, 697727, 1152227, 3102227, 3486227, 5742227, 7488227, 8078627, 8848127, 10837727, 14200127, 23041427, 41870627, 50437727, 59044127, 68766227, 70088927, 91008227, 115141727, 118573727, 122641427

Offset

1,1

Links

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

Example

167*173 = 28891, (28891-2)/7 = 4127 the first entry.

Mathematica

Select[(Times@@@Partition[Prime[Range[5000]], 2, 1]-2)/7, PrimeQ] (* Harvey P. Dale, Sep 03 2015 *)

Prog

(PARI) g(n, p) = { for(x=1, n, y=prime(x)*prime(x+1)-2; if(y%p==0, if(isprime(y/p), print1(y/p", ")))) }

Crossrefs

Cf. A123921.

Sequence in context: A045032 A196896 A210312 * A361413 A339798 A168631

Adjacent sequences: A125499 A125500 A125501 * A125503 A125504 A125505

Keyword

easy,nonn

Author

Cino Hilliard, Dec 28 2006

Extensions

Typo in example corrected by Harvey P. Dale, Sep 03 2015

Status

approved