%I #13 Feb 07 2018 11:45:13
%S 2,3,7,13,61,421,2521,232792561,26771144401,72201776446801,
%T 442720643463713815201,718766754945489455304472257065075294401,
%U 6676878045498705789701874602220118271269436344024536001
%N Primes of the form lcm(1, ..., n) + 1 = A003418(n) + 1.
%H Harvey P. Dale, <a href="/A049536/b049536.txt">Table of n, a(n) for n = 1..16</a>
%e Lcm(9) + 1 = lcm(10) + 1 = 2521, a prime.
%t Select[Table[LCM@@Range[n]+1,{n,150}],PrimeQ]//Union (* _Harvey P. Dale_, May 31 2017 *)
%o (PARI) N=1; print1(2); for(n=1,1e3, if(isprimepower(n,&p), N*=p; if(isprime(N+1), print1(", "N+1)))) \\ _Charles R Greathouse IV_, Nov 18 2015
%Y Subsequence of A070858.
%Y Cf. A003418, A049537, A057824.
%K nonn
%O 1,1
%A _Labos Elemer_
|