The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A089633 Numbers having no more than one 0 in their binary representation. 21
 0, 1, 2, 3, 5, 6, 7, 11, 13, 14, 15, 23, 27, 29, 30, 31, 47, 55, 59, 61, 62, 63, 95, 111, 119, 123, 125, 126, 127, 191, 223, 239, 247, 251, 253, 254, 255, 383, 447, 479, 495, 503, 507, 509, 510, 511, 767, 895, 959, 991, 1007, 1015, 1019, 1021, 1022, 1023 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS A023416(a(n)) <= 1; A023416(a(n)) = A023532(n-2) for n>1; A000120(a(u)) <= A000120(a(v)) for u0: a(n+1) = Min{m>n: BinOnes(a(n))<=BinOnes(m)} with BinOnes=A000120. If m = floor((sqrt(8*n+1) - 1) / 2), then a(n) = 2^(m+1) - 2^(m*(m+3)/2 - n) - 1. - Carl R. White, Feb 10 2009 a(A014132(n)-1) = 2*a(n-1)+1 for n >= 1. - Robert Israel, Dec 14 2018 EXAMPLE From Tilman Piesk, May 09 2012: (Start) This may also be viewed as a triangle:             In binary:                   0                                         0                1     2                                 01       10              3    5    6                          011      101      110            7   11   13   14                  0111     1011     1101     1110         15   23   27   29   30          01111    10111    11011    11101    11110       31  47   55   59   61   62    63   95  111  119  123  125  126 Left three diagonals are A000225,  A055010, A086224. Right diagonal is A000918. Central column is A129868. Numbers in row n (counted from 0) have n binary 1s. (End) MAPLE seq(seq(2^a-1-2^b, b=a-1..0, -1), a=1..11); # Robert Israel, Dec 14 2018 MATHEMATICA fQ[n_] := DigitCount[n, 2, 0] < 2; Select[ Range[0, 2^10], fQ] (* Robert G. Wilson v, Aug 02 2012 *) PROG (Haskell) a089633 n = a089633_list !! (n-1) a089633_list = [2 ^ t - 2 ^ k - 1 | t <- [1..], k <- [t-1, t-2..0]] -- Reinhard Zumkeller, Feb 23 2012 (PARI) {insq(n) = local(dd, hf, v); v=binary(n); hf=length(v); dd=sum(i=1, hf, v[i]); if(dd<=hf-2, -1, 1)} {for(w=0, 1536, if(insq(w)>=0, print1(w, ", ")))} \\ Douglas Latimer, May 07 2013 (PARI) isoka(n) = #select(x->(x==0), binary(n)) <= 1; \\ Michel Marcus, Dec 14 2018 CROSSREFS Cf. A007088, A011371, A014132. Cf. A181741 (primes), union of A081118 and A000918, apart from initial -1. Cf. A265705. Sequence in context: A342392 A053328 A333786 * A003172 A340856 A325100 Adjacent sequences:  A089630 A089631 A089632 * A089634 A089635 A089636 KEYWORD nonn,base AUTHOR Reinhard Zumkeller, Jan 01 2004 STATUS approved

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.

Last modified July 5 05:10 EDT 2022. Contains 355087 sequences. (Running on oeis4.)