A154555 Primes p such that m=(p-1)/2 is the least number such that p divides m!+1.

7, 11, 19, 43, 47, 127, 131, 163, 179, 191, 199, 263, 347, 367, 419, 431, 443, 491, 503, 523, 571, 619, 691, 727, 743, 787, 839, 863, 1051, 1087, 1091, 1123, 1291, 1319, 1367, 1451, 1487, 1499, 1571, 1579, 1583, 1667, 1723, 1783, 1823, 1931, 1951, 2003, 2039

Offset: 1

Author

T. D. Noe, Jan 12 2009

Keywords

• nonn

Comments

The graph of A073944 shows two prominent curves. This sequence gives the primes on the lower curve. Primes on the upper curve are in sequence A154554.

Links

• T. D. Noe, Table of n, a(n) for n=1..1000

Crossrefs

Cf. A073944, A154554.

Programs

Mathematica

Rest[Reap[Do[p=Prime[i]; f=1; m=1; While[f=Mod[f*m,p]; f+1