A139073 Smallest prime number of the form (n+k!)/n.

2, 2, 3, 7, 1009, 2, 5702401, 631, 4481, 13, 566092801, 3, 23452949585516450807808000001, 259201, 337, 2521, 3553839003727872684550301886383176323956736000000001, 41

Offset: 1

Author

Artur Jasinski, Apr 07 2008

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..58

Crossrefs

Cf. A007749, A020458, A082672, A089085, A089130, A117141, A136019, A136020, A136026, A136027, A137390, A139056-A139066, A139068, A139070-A139075.

Programs

Mathematica

a = {}; Do[ k = 1; While[ ! PrimeQ[ (k! + n)/n ], k++ ]; AppendTo[ a, (k! + n)/n ], {n, 1, 100} ]; a [Corrected May 06 2008]

PARI

a(n)=my(k,t);until(denominator(t=k++!/n+1)==1&&ispseudoprime(t),);t \\ Charles R Greathouse IV, Jul 19 2011

Formula

a(n) = (n + A139072(n)!)/n. - Amiram Eldar, Oct 14 2024