A323603 Smallest b > 1 not already in the sequence such that b^(c-1) == 1 (mod c^2), i.e., c is a base-b "Wieferich pseudoprime", where c is the n-th composite number (A002808).

17, 37, 65, 80, 101, 145, 197, 26, 257, 325, 401, 244, 485, 577, 182, 677, 728, 177, 901, 1025, 604, 1157, 99, 1297, 1445, 170, 1601, 1765, 1937, 82, 2117, 2305, 1047, 2501, 2024, 529, 2917, 1451, 3137, 721, 3365, 3601, 3845, 3725, 4097, 168, 1945, 4625, 530

Offset: 1

Author

Felix Fröhlich, Jan 19 2019

Keywords

• nonn

Comments

First differs from A256517 at n = 12.

Is this a permutation of the positive integers > 1?

Crossrefs

Cf. A002808, A256517, A323602.

Programs

PARI

my(v=vector(1)); forcomposite(c=1, 50, my(b=2); while(Mod(b, c^2)^(c-1)!=1, b++; if(Mod(b, c^2)^(c-1)==1, for(k=1, #v, if(b==v[k], b++)))); v=concat(v, b); print1(v[#v], ", "))