The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A153519 Nonprime numbers k such that 10^k == 10 (mod k) and are not Carmichael numbers. 3
 1, 6, 9, 10, 15, 18, 30, 33, 45, 55, 90, 91, 99, 165, 246, 259, 370, 385, 451, 481, 495, 505, 657, 703, 715, 909, 1035, 1045, 1233, 1626, 2035, 2409, 2981, 3333, 3367, 3585, 4005, 4141, 4187, 4521, 4545, 5005, 5461, 6533, 6541, 6565, 7107, 7471, 7777, 8149 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Old name: Members of A121014 which are not Carmichael numbers A002997. LINKS Amiram Eldar, Table of n, a(n) for n = 1..10000 MATHEMATICA Select[Range[8000], !PrimeQ[#] && PowerMod[10, #, #] == Mod[10, #] && !(# > 1 && Divisible[# - 1, CarmichaelLambda[#]]) &] (* Amiram Eldar, Mar 19 2020 *) PROG (PARI) isok(n) = !isprime(n) && !is_A002997(n) && (Mod(10^n, n) == Mod(10, n)); \\ Michel Marcus, Nov 06 2013 CROSSREFS Cf. A002997, A122780, A153508, A153513, A153514, A153515. Sequence in context: A359277 A054020 A121014 * A020219 A175634 A134622 Adjacent sequences: A153516 A153517 A153518 * A153520 A153521 A153522 KEYWORD nonn AUTHOR Artur Jasinski, Dec 28 2008 EXTENSIONS New name from Michel Marcus, Nov 06 2013 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.

Last modified May 25 13:47 EDT 2024. Contains 372788 sequences. (Running on oeis4.)