A262154 Pseudoprimes to base 9, written in base 9.

4, 8, 31, 57, 111, 144, 247, 347, 444, 627, 651, 754, 825, 854, 861, 1261, 1264, 1371, 1457, 1681, 1811, 2102, 2331, 2531, 3338, 3378, 3581, 3631, 3757, 3774, 4011, 4161, 4445, 4551, 5127, 6002, 6321, 6722, 7311, 7547, 8651, 10044, 10101, 10637, 11111, 11762, 12464, 12831, 12885, 13141, 13201, 15461, 16084, 16451

Offset: 1

Author

Abdul Gaffar Khan, Sep 13 2015

Keywords

• nonn
• base

Links

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

Crossrefs

Cf. A007095 (numbers in base 9), A020138 (pseudoprimes to base 9).

Cf. A258189, A262101, A262102, A262103, A262104, A262105.

Programs

Mathematica

base = 9; t = {}; n = 1;
While[Length[t] < 80, n++;
If[! PrimeQ[n] && PowerMod[base, n - 1, n] == 1,
  AppendTo[t, FromDigits@IntegerDigits[n, 9]]]]; t

PARI

lista(nn, b=9) = {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) = A007095(A020138(n)).