A089633 Numbers having no more than one 0 in their binary representation.
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
Offset: 0
Examples
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) From _Gus Wiseman_, May 24 2024: (Start) The terms together with their binary expansions and binary indices begin: 0: 0 ~ {} 1: 1 ~ {1} 2: 10 ~ {2} 3: 11 ~ {1,2} 5: 101 ~ {1,3} 6: 110 ~ {2,3} 7: 111 ~ {1,2,3} 11: 1011 ~ {1,2,4} 13: 1101 ~ {1,3,4} 14: 1110 ~ {2,3,4} 15: 1111 ~ {1,2,3,4} 23: 10111 ~ {1,2,3,5} 27: 11011 ~ {1,2,4,5} 29: 11101 ~ {1,3,4,5} 30: 11110 ~ {2,3,4,5} 31: 11111 ~ {1,2,3,4,5} 47: 101111 ~ {1,2,3,4,6} 55: 110111 ~ {1,2,3,5,6} 59: 111011 ~ {1,2,4,5,6} 61: 111101 ~ {1,3,4,5,6} 62: 111110 ~ {2,3,4,5,6} (End)
Links
- Reinhard Zumkeller, Table of n, a(n) for n = 0..10000
- Vladimir Shevelev, On the Basis Polynomials in the Theory of Permutations with Prescribed Up-Down Structure, arXiv:0801.0072 [math.CO], 2007-201. See Section 14.
- Vladimir Shevelev, Binomial Coefficient Predictors, Journal of Integer Sequences, Vol. 14 (2011), Article 11.2.8.
- Vladimir Shevelev, The number of permutations with prescribed up-down structure as a function of two variables, INTEGERS, 12 (2012), #A1.
- Index entries for sequences related to binary expansion of n.
Crossrefs
Programs
-
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
-
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 *)
-
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
-
Python
from itertools import count, islice def A089633_gen(): # generator of terms return ((1<
A089633_list = list(islice(A089633_gen(),30)) # Chai Wah Wu, Feb 10 2023 -
Python
from math import isqrt, comb def A089633(n): return (1<<(a:=(isqrt((n<<3)+1)-1>>1)+1))-(1<
Chai Wah Wu, Dec 19 2024
Formula
a(0)=0, n>0: 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
Comments