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A050992 4-Knödel numbers. 11
6, 8, 12, 16, 20, 24, 28, 40, 44, 48, 52, 60, 68, 76, 80, 92, 112, 116, 120, 124, 148, 154, 164, 172, 188, 208, 212, 236, 240, 244, 264, 268, 280, 284, 292, 316, 332, 340, 356, 364, 388, 404, 412, 428, 436, 452, 508, 520, 524, 548, 556, 596, 604, 628, 652 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..55.

Eric Weisstein's World of Mathematics, Knödel Numbers.

MAPLE

with(numtheory);

knodel:=proc(i, k)

local a, n, ok;

for n from k+1 to i do

  ok:=1;

  for a from 1 to n do

     if gcd(a, n)=1 then  if (a^(n-k) mod n)<>1 then ok:=0; break; fi; fi;

  od;

  if ok=1 then print(n); fi;

od;

end:

knodel(1000, 4) # Paolo P. Lava, Feb 24 2012

MATHEMATICA

Select[Range[6, 1000, 2], Divisible[# - 4, CarmichaelLambda[#]]&] (* Jean-François Alcover, Mar 01 2018 *)

CROSSREFS

Cf. A002997, A050990, A033553, A050993, A208154-A208158.

Sequence in context: A177085 A194409 A115166 * A090259 A089241 A280270

Adjacent sequences:  A050989 A050990 A050991 * A050993 A050994 A050995

KEYWORD

nonn

AUTHOR

Eric W. Weisstein

STATUS

approved

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Last modified December 15 09:08 EST 2018. Contains 318148 sequences. (Running on oeis4.)