A098027 Smallest prime p such that p+2 is a product of exactly n distinct primes.

3, 13, 103, 1153, 15013, 255253, 4849843, 111546433, 4360010653, 100280245063, 5245694198743, 152125131763603, 7149881192889433, 421842990380476663, 16294579238595022363, 1106494163767990292293, 74135108972455349583763

Offset

1,1

Comments

In most cases a(n) = pn! - 2, where pn! is "factorial of odd primes": from 3 to n-th odd prime. - Zak Seidov - Zak Seidov and Don Reble, Mar 10 2006

Links

Table of n, a(n) for n=1..17.

Example

3+2=5 (1 prime), 13+2=15=3*5 (2 primes), 103+2=105=3*5*7 (3 primes), ...
1153 is the 4th entry in the sequence because it is followed by primes 1783, 1993, 2143, 2803, ... with the property 1153+2 = 3*5*7*11, 1783+2 = 3*5*7*17, 1993+2 = 3*5*7*19, 2143+2 = 3*5*11*13, 2803+2 = 3*5*11*17, ...

Crossrefs

Cf. A067024 [From R. J. Mathar, Sep 02 2008]

Sequence in context: A068168 A215126 A228148 * A357247 A182104 A073587

Adjacent sequences: A098024 A098025 A098026 * A098028 A098029 A098030

Keyword

nonn

Author

Lekraj Beedassy, Sep 10 2004

Extensions

Extended by Ray Chandler, Sep 18 2004

More terms from Zak Seidov and Don Reble, Mar 10 2006

Corrected by Don Reble, Apr 03 2006

Status

approved