A067658 - OEIS

%I #9 Jul 20 2019 08:06:54

%S 7,47,79,103,127,191,199,263,367,383,431,479,503,599,607,631,727,743,

%T 823,839,863,887,991,1087,1151,1319,1367,1423,1487,1511,1583,1663,

%U 1783,1823,1871,1951,2039,2063,2111,2143,2287,2311,2383,2423,2447,2503,2551

%N Odd integers k such that k = gcd(((k-1)/2)!+1, ((k-1)/2)^((k-1)/2)+1).

%C gcd(k!+1, k^k+1)= 1 or 2k+1 with 2k+1 prime but if 2m+1 is prime 2m+1 is not necessarily in the sequence.

%K nonn

%O 1,1

%A _Benoit Cloitre_, Feb 03 2002