A098061 Primes p such that p - 6 is a product of two consecutive primes.

41, 83, 149, 227, 443, 673, 1153, 1523, 2027, 4093, 5189, 6563, 7393, 9803, 11027, 12323, 20717, 39209, 47059, 50627, 60497, 64513, 70753, 95483, 104933, 123203, 126733, 131759, 136897, 154439, 181457, 186629, 190093, 194483, 213449, 233279, 251003, 256033

Offset

1,1

Comments

Is this sequence infinite?

Links

K. D. Bajpai, Table of n, a(n) for n = 1..10000

Example

prime(3)*prime(4) = 35. 35+6 = 41, the first entry in the table.

Mathematica

f[n_]:=Prime[n]*Prime[n+1]+6; lst={}; Do[If[PrimeQ[f[n]], AppendTo[lst, f[n]]], {n, 6!}]; lst (* Vladimir Joseph Stephan Orlovsky, Feb 10 2010 *)
Select[Times@@#+6&/@Partition[Prime[Range[100]], 2, 1], PrimeQ]  (* Harvey P. Dale, Apr 25 2011 *)

Prog

(PARI) f(n, m) = for(x=2, n, z=(prime(x+1)*prime(x)); if(isprime(z+m), print1(z+m", ")))
(PARI) is(n)=if(n<9, return(0)); my(q=precprime(sqrtint(n-6))); n-6==q*nextprime(q+1) && isprime(n) \\ Charles R Greathouse IV, Jul 22 2013

Crossrefs

Sequence in context: A375138 A173550 A136072 * A141898 A054998 A067378

Adjacent sequences: A098058 A098059 A098060 * A098062 A098063 A098064

Keyword

easy,nonn

Author

Cino Hilliard, Sep 11 2004

Status

approved