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A020156 Pseudoprimes to base 28. 1
9, 27, 45, 87, 145, 261, 361, 529, 561, 703, 783, 785, 1105, 1305, 1413, 1431, 1885, 2041, 2413, 2465, 2871, 3201, 3277, 4553, 4699, 5149, 5181, 5365, 7065, 8149, 8321, 8401, 9841, 10027, 10585, 12673, 13333, 13345, 13357, 13833, 14383, 14769, 14981 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Composite numbers n such that 28^(n-1) == 1 (mod n). - Michel Lagneau, Feb 18 2012

LINKS

T. D. Noe, Table of n, a(n) for n = 1..1000

Index entries for sequences related to pseudoprimes

MATHEMATICA

base = 28; t = {}; n = 1; While[Length[t] < 100, n++; If[! PrimeQ[n] && PowerMod[base, n-1, n] == 1, AppendTo[t, n]]]; t (* T. D. Noe, Feb 21 2012 *)

CROSSREFS

Cf. A001567 (pseudoprimes to base 2).

Sequence in context: A103965 A069069 A031088 * A287661 A062231 A133636

Adjacent sequences:  A020153 A020154 A020155 * A020157 A020158 A020159

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified June 25 10:29 EDT 2019. Contains 324351 sequences. (Running on oeis4.)