%I #17 Jul 14 2017 11:28:14
%S 0,0,1,0,1,0,1,0,3,2,1,0,1,2,3,0,1,0,1,0,3,2,1,0,5,2,9,4,1,2,1,0,3,2,
%T 11,0,1,2,3,0,1,0,1,4,9,2,1,0,7,10,3,4,1,0,15,2,3,2,1,0,1,2,3,0,5,6,1,
%U 4,3,10,1,0,1,2,15,4,17,6,1,0,27,2,1,0,5
%N a(n) = n mod lambda(n) where lambda is the Carmichael function (A002322).
%C a(n) = A068494(n) for n = 1..14.
%C a(k) = 1 for k = prime(n) > 2 or k = A002997(n).
%C a(n) is the smallest k >= 0 such that b^(n-k) == 1 (mod n) for every b coprime to n. - _Thomas Ordowski_, Jun 30 2017
%H Michel Lagneau, <a href="/A219175/b219175.txt">Table of n, a(n) for n = 1..10000</a>
%e a(9) = 3 because lambda(9) = 6 and 9 == 3 mod 6.
%p with(numtheory):for n from 1 to 100 do: x:=irem(n,lambda(n)): printf(`%d, `,x):od:
%t Table[Mod[n, CarmichaelLambda[n]], {n, 100}] (* _T. D. Noe_, Nov 13 2012 *)
%o (PARI) a(n)=n%lcm(znstar(n)[2]) \\ _Charles R Greathouse IV_, Nov 13 2012
%Y Cf. A068494, A002322, A002997.
%K nonn
%O 1,9
%A _Michel Lagneau_, Nov 13 2012
|