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A174435
lambda(y)/x, where y an odd squarefree semiprime and x = ord(2,y) the smallest positive integer such that 2^x == 1 mod y (the multiplicative order of 2 mod y).
2
1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 3, 1, 1, 1, 2, 2, 3, 1, 1, 1, 1, 3, 1, 2, 1, 1, 1, 2, 1, 1, 2, 1, 1, 3, 2, 4, 2, 1, 1, 1, 1, 1, 1, 1, 4, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 2, 1, 4, 3, 1, 2, 1, 1, 9, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 5, 1, 3, 3, 1, 2, 1, 2, 2, 1, 1, 8, 1, 1, 1, 6
OFFSET
1,6
LINKS
Vassilis Papadimitriou, Table of n, a(n) for n=1,...,10000.
FORMULA
Equals lambda(A046388)/ord(2, A046388), or lambda(A046388)/A174240.
a(n) = A002322(A046388(n))/A002326((A046388(n)+1)/2). - Amiram Eldar, Feb 24 2021
EXAMPLE
For n=1 the a(1)= 1, as the first odd squarefree semiprime is 15, lambda(15)=4 and ord(2,15)=4
MATHEMATICA
(CarmichaelLambda[#]/MultiplicativeOrder[2, #]) & /@ Select[Range[1, 530, 2], PrimeOmega[#] == 2 && PrimeNu[#] == 2 &] (* Amiram Eldar, Feb 24 2021 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved