cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A262103 Pseudoprimes to base 6, written in base 6.

Original entry on oeis.org

55, 505, 1001, 1221, 2121, 5041, 5051, 5501, 10101, 12001, 15225, 20301, 21021, 23501, 24301, 24341, 30041, 31031, 32451, 42241, 50125, 50321, 101101, 102421, 105131, 111111, 113425, 121001, 121101, 123041, 123321, 132305, 150135, 152021, 201201, 204445, 212121, 221001, 222401, 232401
Offset: 1

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Author

Abdul Gaffar Khan, Sep 11 2015

Keywords

Crossrefs

Cf. A007092 (numbers in base 6), A005937 (pseudoprimes to base 6).

Programs

  • Mathematica
    base = 6; t = {}; n = 1;
    While[Length[t] < 40, n++;
    If[! PrimeQ[n] && PowerMod[base, n - 1, n] == 1,
      AppendTo[t, FromDigits@IntegerDigits[n, 6]]]]; t
  • PARI
    lista(nn, b=6) = {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) = A007092(A005937(n)).