A067658 Odd integers k such that k = gcd(((k-1)/2)!+1, ((k-1)/2)^((k-1)/2)+1).

7, 47, 79, 103, 127, 191, 199, 263, 367, 383, 431, 479, 503, 599, 607, 631, 727, 743, 823, 839, 863, 887, 991, 1087, 1151, 1319, 1367, 1423, 1487, 1511, 1583, 1663, 1783, 1823, 1871, 1951, 2039, 2063, 2111, 2143, 2287, 2311, 2383, 2423, 2447, 2503, 2551

Offset: 1

Author

Benoit Cloitre, Feb 03 2002

Keywords

• nonn

Comments

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.