A110336 Smallest prime of the form 2n*(2n+2)*(2n+4)*...*(2n+2k) + 1 where k is a nonnegative integer.

3, 5, 7, 13441, 11, 13, 929901772801, 17, 19, 7380172801, 23, 20530298881, 21841, 29, 31, 59535361, 7591472824321, 37, 63841, 41, 43, 32611799187695769164215700373287163408678912000001, 47

Offset

1,1

Links

Table of n, a(n) for n=1..23.

Example

a(4) = 8*10*12*14 + 1 = 13441, 8 + 1, 8*10 + 1, 8*10*12 + 1 are all composite.

Mathematica

Do[p = k = 2*n; While[ !PrimeQ[p+1], k += 2; p *= k]; Print[p+1], {n, 1, 30}] (* Ryan Propper, Aug 15 2005 *)

Crossrefs

Sequence in context: A288212 A273010 A073691 * A073695 A268694 A068825

Adjacent sequences: A110333 A110334 A110335 * A110337 A110338 A110339

Keyword

nonn,more

Author

Amarnath Murthy, Jul 20 2005

Extensions

More terms from Ryan Propper, Aug 15 2005

Status

approved