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A153514
Terms of A122780 which are not Carmichael numbers A002997.
5
1, 6, 66, 91, 121, 286, 671, 703, 726, 949, 1541, 1891, 2665, 2701, 3281, 3367, 3751, 4961, 5551, 7107, 7381, 8205, 8401, 8646, 11011, 12403, 14383, 15203, 15457, 16471, 16531, 18721, 19345, 23521, 24046, 24661, 24727, 28009, 29161, 30857, 31621
OFFSET
1,2
COMMENTS
For the intersection of this sequence and A153508, see A153513.
LINKS
MAPLE
filter:= proc(n) local p;
if isprime(n) or (3 &^n - 3 mod n <> 0) then return false fi;
if n::even then return true fi;
if not numtheory:-issqrfree(n) then return true fi;
for p in numtheory:-factorset(n) do
if n-1 mod (p-1) <> 0 then return true fi
od;
false
end proc:
filter(1):= true:
select(filter, [$1..10^5]); # Robert Israel, Jan 29 2017
MATHEMATICA
okQ[n_] := !PrimeQ[n] && PowerMod[3, n, n] == Mod[3, n] && Mod[n, CarmichaelLambda[n]] != 1;
Select[Range[10^5], okQ] (* Jean-François Alcover, Mar 27 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Artur Jasinski, Dec 28 2008
STATUS
approved