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A208157
9-Knödel numbers.
8
21, 27, 45, 63, 99, 105, 117, 153, 171, 189, 207, 261, 273, 279, 333, 369, 387, 423, 429, 477, 513, 531, 549, 585, 603, 639, 657, 711, 747, 801, 873, 909, 927, 945, 963, 981, 1017, 1143, 1179, 1197, 1209, 1233, 1251, 1341, 1359, 1365, 1413, 1467, 1503, 1557
OFFSET
1,1
LINKS
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 *)
KEYWORD
nonn
AUTHOR
Paolo P. Lava, Feb 24 2012
STATUS
approved