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a(n) = lambda(phi(n)) where lambda(n) (A002322) is the Carmichael lambda function which gives the smallest integer m such that k^m = 1 mod n for all integers k relatively prime to n and phi(n) is A000010.
4

%I #10 Aug 22 2017 12:02:25

%S 1,1,1,1,2,1,2,2,2,2,4,2,2,2,2,2,4,2,6,2,2,4,10,2,4,2,6,2,6,2,4,4,4,4,

%T 2,2,6,6,2,4,4,2,6,4,2,10,22,4,6,4,8,2,12,6,4,2,6,6,28,4,4,4,6,8,4,4,

%U 10,8,10,2,12,2,6,6,4,6,4,2,12,8,18,4,40,2,16,6,6,4,10,2,6,10,4,22,6,8

%N a(n) = lambda(phi(n)) where lambda(n) (A002322) is the Carmichael lambda function which gives the smallest integer m such that k^m = 1 mod n for all integers k relatively prime to n and phi(n) is A000010.

%H Charles R Greathouse IV, <a href="/A077197/b077197.txt">Table of n, a(n) for n = 1..10000</a>

%t Table[CarmichaelLambda[EulerPhi[n]], {n, 1, 100}]

%o (PARI) a(n)=lcm(znstar(eulerphi(n))[2]) \\ _Charles R Greathouse IV_, Feb 21 2013

%Y Cf. A000010, A002322, A206941.

%K nonn

%O 1,5

%A _Joseph L. Pe_, Nov 29 2002