1,4

This is not the same sequence as sequence A032742, where A032742(n) = the largest proper divisor of n. See A146077 for numbers n such that the sequences A032742 and A159353 differ.

Table of n, a(n) for n=1..84.

a(n) = Denominator((2^n - 2)/n). - Juri-Stepan Gerasimov, Sep 09 2014

(MAGMA) [Denominator((2^n-2)/n): n in [1..84]]; // Juri-Stepan Gerasimov, Sep 09 2014

(PARI) a(n)=my(k=1); while((2^n-2)*k%n != 0, k++); return(k) \\ Edward Jiang, Sep 09 2014

(PARI) a(n)=denominator(lift(Mod(2, n)^n-2)/n) \\ Charles R Greathouse IV, Sep 11 2014

Cf. A000918, A146077.

Sequence in context: A079554 A247892 A079880 * A032742 A060654 A291329

Adjacent sequences: A159350 A159351 A159352 * A159354 A159355 A159356

nonn

Leroy Quet, Apr 11 2009

Extended by Ray Chandler, Apr 11 2009

approved