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

1,6

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

Cf. A002322, A002326, A046388, A174240.

Sequence in context: A275811 A102855 A124148 * A330749 A294883 A348940

Adjacent sequences: A174432 A174433 A174434 * A174436 A174437 A174438

Keyword

nonn

Author

Vassilis Papadimitriou, Mar 19 2010

Status

approved