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).
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
Keywords
Examples
For n=1 the a(1)= 1, as the first odd squarefree semiprime is 15, lambda(15)=4 and ord(2,15)=4
Links
- Vassilis Papadimitriou, Table of n, a(n) for n=1,...,10000.
Programs
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Mathematica
(CarmichaelLambda[#]/MultiplicativeOrder[2, #]) & /@ Select[Range[1, 530, 2], PrimeOmega[#] == 2 && PrimeNu[#] == 2 &] (* Amiram Eldar, Feb 24 2021 *)