A258189 Pseudoprimes to base 3, written in base 3.

10101, 11111, 101121, 220212, 222001, 1022011, 1111221, 2010002, 2101001, 2121001, 10101022, 10122201, 10201001, 10212111, 11111112, 11121201, 12010221, 20210202, 21121121, 100001111, 101010101, 102112011, 110020001, 112112001, 120002211, 122000101, 201201201, 202212002

Offset: 1

Author

Abdul Gaffar Khan, Sep 11 2015

Keywords

• nonn
• base

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A005935 (pseudoprimes to base 3), A007089 (numbers in base 3).

Cf. A262101, A262102, A262103, A262104, A262105, A262154.

Programs

Mathematica

base = 3; t = {}; n = 1;
While[Length[t] < 40, n++;
If[! PrimeQ[n] && PowerMod[base, n - 1, n] == 1,
  AppendTo[t, FromDigits@IntegerDigits[n, 3]]]]; t

PARI

lista(nn, b=3) = {for (n=1, nn, if (Mod(b, n)^(n-1)==1 && !ispseudoprime(n) && n>1, print1(subst(Pol(digits(n,b), x), x, 10), ", ");););} \\ Michel Marcus, Sep 30 2015

Formula

a(n) = A007089(A005935(n)). - Michel Marcus, Sep 11 2015

Extensions

a(25) corrected by Georg Fischer, Dec 18 2020