OFFSET
1,1
COMMENTS
According to Karsten Meyer, May 16 2006, 10 should be excluded, following the strict definition in Crandall and Pomerance.
Composite numbers n such that 11^(n-1) == 1 (mod n).
REFERENCES
R. Crandall and C. Pomerance, "Prime Numbers - A Computational Perspective", Second Edition, Springer Verlag 2005, ISBN 0-387-25282-7 Page 132 (Theorem 3.4.2. and Algorithm 3.4.3)
J.-M. De Koninck, Ces nombres qui nous fascinent, Entry 190, p. 57, Ellipses, Paris 2008.
LINKS
R. J. Mathar and T. D. Noe, Table of n, a(n) for n = 1..1000 (R. J. Mathar to 726 terms)
F. Richman, Primality testing with Fermat's little theorem
MATHEMATICA
base = 11; 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
KEYWORD
nonn
AUTHOR
STATUS
approved