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A262154
Pseudoprimes to base 9, written in base 9.
7
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
1,1
LINKS
FORMULA
a(n) = A007095(A020138(n)).
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
PROG
(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
CROSSREFS
Cf. A007095 (numbers in base 9), A020138 (pseudoprimes to base 9).
Sequence in context: A020331 A248476 A082595 * A080072 A374319 A149091
KEYWORD
nonn,base
AUTHOR
Abdul Gaffar Khan, Sep 13 2015
STATUS
approved