A075104 Greatest common divisor of n and integer part of log_2(n).

1, 1, 1, 2, 1, 2, 1, 1, 3, 1, 1, 3, 1, 1, 3, 4, 1, 2, 1, 4, 1, 2, 1, 4, 1, 2, 1, 4, 1, 2, 1, 1, 1, 1, 5, 1, 1, 1, 1, 5, 1, 1, 1, 1, 5, 1, 1, 1, 1, 5, 1, 1, 1, 1, 5, 1, 1, 1, 1, 5, 1, 1, 1, 2, 1, 6, 1, 2, 3, 2, 1, 6, 1, 2, 3, 2, 1, 6, 1, 2, 3, 2, 1, 6, 1, 2, 3, 2, 1, 6, 1, 2, 3, 2, 1, 6, 1, 2, 3, 2, 1, 6, 1, 2, 3, 2

Offset: 1

Author

Reinhard Zumkeller, Sep 02 2002

Keywords

• nonn

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000523, A075105, A075106.

Programs

Haskell

a075104 n = gcd n $ a000523 n  -- Reinhard Zumkeller, Jul 08 2014

Mathematica

Table[GCD[n,IntegerPart[Log[2,n]]],{n,110}] (* Harvey P. Dale, Apr 21 2016 *)

Formula

a(n) = gcd(n, A000523(n)).