login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

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).

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

Sequence in context: A020331 A248476 A082595 * A080072 A149091 A149092

Adjacent sequences:  A262151 A262152 A262153 * A262155 A262156 A262157

KEYWORD

nonn,base

AUTHOR

Abdul Gaffar Khan, Sep 13 2015

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 13 17:37 EDT 2022. Contains 356107 sequences. (Running on oeis4.)