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!)
A094779 Let 2^k = smallest power of 2 >= binomial(n,[n/2]); a(n) = 2^k - binomial(n,[n/2]). 2

%I #6 Jun 25 2015 06:41:29

%S 0,0,0,1,2,6,12,29,58,2,4,50,100,332,664,1757,3514,8458,16916,38694,

%T 77388,171572,343144,745074,1490148,3188308,6376616,13496132,26992264,

%U 56658968,113317936,236330717,472661434,980680538,1961361076,4052366942,8104733884

%N Let 2^k = smallest power of 2 >= binomial(n,[n/2]); a(n) = 2^k - binomial(n,[n/2]).

%C Suggested by reading the Knuth article.

%C a(n+1) < a(n) for n = 8, 40, 162, 650... - _Ivan Neretin_, Jun 25 2015

%D D. E. Knuth, Efficient balanced codes, IEEE Trans. Inform. Theory, 32 (No. 1, 1986), 51-53.

%H Ivan Neretin, <a href="/A094779/b094779.txt">Table of n, a(n) for n = 0..1000</a>

%e C(30,15) = 155117520; 2^28 = 268435456; difference is 113317936.

%t Table[-(b = Binomial[n, Quotient[n, 2]]) + 2^Ceiling[Log2[b]], {n, 0, 36}] (* _Ivan Neretin_, Jun 25 2015 *)

%Y Cf. A093387, A094780.

%K nonn

%O 0,5

%A _N. J. A. Sloane_, Jun 10 2004

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 June 7 05:40 EDT 2024. Contains 373144 sequences. (Running on oeis4.)