cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A072600 Numbers which in base 2 have fewer 0's than 1's.

Original entry on oeis.org

1, 3, 5, 6, 7, 11, 13, 14, 15, 19, 21, 22, 23, 25, 26, 27, 28, 29, 30, 31, 39, 43, 45, 46, 47, 51, 53, 54, 55, 57, 58, 59, 60, 61, 62, 63, 71, 75, 77, 78, 79, 83, 85, 86, 87, 89, 90, 91, 92, 93, 94, 95, 99, 101, 102, 103, 105, 106, 107, 108, 109, 110, 111, 113, 114, 115
Offset: 1

Views

Author

Reinhard Zumkeller, Jun 23 2002

Keywords

Comments

A037861(a(n)) < 0.
b_k = {a(n) | for all n s.t. a(n) contains k binary digits equal to 1} is the list of all valid win/loss round sequences in a "best of 2k-1" two player game, where 1 is a win and 0 is a loss. For example 19 = 10011b represents a game where the winner won the first two rounds, lost the next two, and won the last one. |b_k| = A001700(k). - Philippe Beaudoin, May 14 2014

Examples

			11 is present because '1011' contains 1 '0' and 3 '1's: 1<3.
		

Crossrefs

Programs

  • Haskell
    a072600 n = a072600_list !! (n-1)
    a072600_list = filter ((< 0) . a037861) [0..]
    -- Reinhard Zumkeller, Mar 31 2015
    
  • Mathematica
    Select[Range[130],DigitCount[#,2,0]Harvey P. Dale, Jan 12 2011 *)
  • PARI
    is(n)=2*hammingweight(n)>exponent(n)+1 \\ Charles R Greathouse IV, Apr 18 2020