OFFSET
1,1
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
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(10000, 9)
MATHEMATICA
Select[Range[12, 1560, 3], Divisible[# - 9, CarmichaelLambda[#]]&] (* Jean-François Alcover, Mar 01 2018 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Paolo P. Lava, Feb 24 2012
STATUS
approved