login
Smallest prime number of the form (n+k!)/n.
1

%I #14 Oct 14 2024 01:37:20

%S 2,2,3,7,1009,2,5702401,631,4481,13,566092801,3,

%T 23452949585516450807808000001,259201,337,2521,

%U 3553839003727872684550301886383176323956736000000001,41

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

%H Amiram Eldar, <a href="/A139073/b139073.txt">Table of n, a(n) for n = 1..58</a>

%F a(n) = (n + A139072(n)!)/n. - _Amiram Eldar_, Oct 14 2024

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

%o (PARI) a(n)=my(k,t);until(denominator(t=k++!/n+1)==1&&ispseudoprime(t),);t \\ _Charles R Greathouse IV_, Jul 19 2011

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

%K nonn

%O 1,1

%A _Artur Jasinski_, Apr 07 2008