A178253 a(n) is the least positive integer m such that (A001969(n))^m is in A000069.

4, 2, 4, 2, 2, 4, 4, 2, 2, 2, 2, 4, 5, 2, 4, 2, 2, 2, 2, 2, 2, 3, 2, 4, 2, 4, 5, 5, 2, 4, 4, 2, 2, 2, 2, 2, 2, 2, 2, 2, 4, 2, 2, 2, 3, 2, 2, 4, 3, 2, 2, 5, 4, 5, 3, 2, 5, 2, 3, 4, 3, 2, 4, 2, 2, 2, 2, 2, 2, 4, 2, 2, 2, 2, 2, 2, 2, 2, 4, 2, 2, 3, 4, 2, 2, 2, 2, 4, 2, 3, 3, 2, 3, 2, 2, 4, 3, 2, 3, 2, 2, 2, 3, 2, 5

Offset

2,1

Comments

Conjecture: a(n) exists for all n >= 2.

The values of A001969(n)^m are given in A178373. [From Jeremy Gardiner, May 26 2010]

Links

Charles R Greathouse IV, Table of n, a(n) for n = 2..10000

Formula

If k=A001969(n)=2^m*A001969(s), where A001969(s) is odd, then a(n)=a(s).

Prog

(PARI) a(n)=my(e=2*n--+hammingweight(n)%2, m=1); e>>=valuation(e, 2);  while(hammingweight(e^m++)%2==0, ); m \\ Charles R Greathouse IV, Mar 22 2013

Crossrefs

Cf. A000069, A001969, A178373.

Sequence in context: A269592 A105256 A064127 * A209272 A105397 A328999

Adjacent sequences: A178250 A178251 A178252 * A178254 A178255 A178256

Keyword

nonn,easy

Author

Vladimir Shevelev, May 24 2010, May 25 2010

Extensions

Extended by Jeremy Gardiner, May 26 2010

Edited by N. J. A. Sloane, Jun 08 2010

Status

approved