The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A268514 a(0)=0; thereafter a(2n+1)=3*a(n)+1, a(2n)=2*a(n)+a(n-1)+1. 2

%I #13 Feb 14 2016 18:52:52

%S 0,1,3,4,8,10,12,13,21,25,29,31,35,37,39,40,56,64,72,76,84,88,92,94,

%T 102,106,110,112,116,118,120,121,153,169,185,193,209,217,225,229,245,

%U 253,261,265,273,277,281,283,299,307,315,319,327,331,335,337

%N a(0)=0; thereafter a(2n+1)=3*a(n)+1, a(2n)=2*a(n)+a(n-1)+1.

%H Colin Barker, <a href="/A268514/b268514.txt">Table of n, a(n) for n = 0..1000</a>

%F a(n) = Sum{i=1..n} 2^{number of 0's in binary expansion of i}.

%F a(n) = (A064194(n+1)-1)/2.

%o (PARI) a(n) = sum(i=1, n, b=binary(i); 2^(#b-norml2(b))) \\ _Colin Barker_, Feb 08 2016

%Y Cf. A064194, A023416 (no. of 0's in n).

%Y First differences are (essentially) A080100.

%K nonn

%O 0,3

%A _N. J. A. Sloane_, Feb 07 2016

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 28 06:48 EDT 2024. Contains 372903 sequences. (Running on oeis4.)