This site is supported by donations to The OEIS Foundation.

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A033053 Numbers n such that base 2 representation Sum{d(i)*2^i: i=0,1,...,m} has d(i)=1 when i<>m mod 2 3
 1, 3, 6, 7, 13, 15, 26, 27, 30, 31, 53, 55, 61, 63, 106, 107, 110, 111, 122, 123, 126, 127, 213, 215, 221, 223, 245, 247, 253, 255, 426, 427, 430, 431, 442, 443, 446, 447, 490, 491, 494, 495, 506, 507, 510, 511, 853, 855, 861, 863 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Numbers 2^(2k)-1 - A062880(m) where 2^(2k-2) >= A062880(m) or 2^(2k+1)-1 - A000695(m) where 2^(2k-1) >= A000695(m). - Franklin T. Adams-Watters, Aug 30 2014 LINKS Robert Israel, Table of n, a(n) for n = 1..12286 FORMULA a(2j+2) = 4 a(j)+3, a(2j+1) = 4 a(j) + 2 if j <= 3*2^(m-1)-2, a(2j+1) = 4 a(j) + 1 otherwise, where m = floor(log_2(j+1)) EXAMPLE 26 = 11010_2 has m=4, and d(i) = 1 for i=1 and 3 53 = 110101_2 has m=5, and d(i) = 1 for i=0, 2 and 4 MAPLE F:= proc(m)    local n0, j, S;    n0:= 2^m + add(2^(m-1-2*j), j=0..floor((m-1)/2));    S:= combinat[powerset]({seq(2^(m-2*j), j=1..floor(m/2))});    map(t -> convert(t, `+`)+n0, S); end; `union`(seq(F(m), m=0..24)}; # Robert Israel, Mar 30 2014 CROSSREFS Cf. A126684, A000695, A062880. Sequence in context: A176301 A191290 A137595 * A248388 A107850 A216514 Adjacent sequences:  A033050 A033051 A033052 * A033054 A033055 A033056 KEYWORD nonn,base AUTHOR EXTENSIONS Definition corrected, incorrect cross-reference removed, and recurrence formulas by Robert Israel, Mar 30 2014 STATUS approved

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

Last modified January 17 16:53 EST 2019. Contains 319235 sequences. (Running on oeis4.)