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

1,1

Comments

First differs from A256517 at n = 12.

Is this a permutation of the positive integers > 1?

Links

Table of n, a(n) for n=1..49.

Prog

(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], ", "))

Crossrefs

Cf. A002808, A256517, A323602.

Sequence in context: A146348 A050952 A256517 * A200865 A319245 A093930

Adjacent sequences: A323600 A323601 A323602 * A323604 A323605 A323606

Keyword

nonn

Author

Felix Fröhlich, Jan 19 2019

Status

approved