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.

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A107911 Numbers having consecutive zeros and also consecutive ones in binary representation.

Original entry on oeis.org

12, 19, 24, 25, 28, 35, 38, 39, 44, 48, 49, 50, 51, 52, 56, 57, 60, 67, 70, 71, 75, 76, 77, 78, 79, 83, 88, 89, 92, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 108, 112, 113, 114, 115, 116, 120, 121, 124, 131, 134, 135, 139, 140, 141, 142, 143, 147, 150, 151, 152
Offset: 1

Views

Author

Reinhard Zumkeller, May 28 2005

Keywords

Crossrefs

Intersection of A004753 and A004780.
Complement of A107909.

Programs

  • Mathematica
    czcoQ[n_]:=Module[{c2=Partition[IntegerDigits[n,2],2,1]},MemberQ[c2,{0,0}]&&MemberQ[c2,{1,1}]]; Select[Range[200],czcoQ] (* Harvey P. Dale, Jul 24 2012 *)
  • Python
    def ok(n): b = bin(n)[2:]; return "00" in b and "11" in b
    print([k for k in range(153) if ok(k)]) # Michael S. Branicky, Dec 19 2021

Extensions

Offset changed to 1 by Michael S. Branicky, Dec 19 2021

A300302 Square array T(n, k) (n >= 1, k >= 1) read by antidiagonals upwards: T(n, k) is the k-th positive number whose binary representation contains the binary representation of n as a substring.

Original entry on oeis.org

1, 2, 2, 3, 4, 3, 4, 6, 5, 4, 5, 8, 7, 6, 5, 6, 10, 9, 11, 8, 6, 7, 12, 11, 12, 12, 9, 7, 8, 14, 13, 13, 16, 13, 10, 8, 9, 16, 15, 14, 20, 17, 14, 11, 9, 10, 18, 17, 23, 22, 21, 18, 15, 12, 10, 11, 20, 19, 24, 28, 24, 22, 19, 19, 13, 11, 12, 22, 21, 25, 32, 29
Offset: 1

Views

Author

Rémy Sigrist, Mar 08 2018

Keywords

Comments

Each positive number k appears A122953(k) times in this array.

Examples

			Square array begins:
  n\k|    1    2    3    4    5    6    7    8    9   10
  ---+--------------------------------------------------
    1|    1    2    3    4    5    6    7    8    9   10  <--  A000027
    2|    2    4    5    6    8    9   10   11   12   13  <--  A062289
    3|    3    6    7   11   12   13   14   15   19   22  <--  A004780
    4|    4    8    9   12   16   17   18   19   20   24  <--  A004753
    5|    5   10   11   13   20   21   22   23   26   27  <--  A004748
    6|    6   12   13   14   22   24   25   26   27   28  <--  A004749
    7|    7   14   15   23   28   29   30   31   39   46  <--  A004781
    8|    8   16   17   24   32   33   34   35   40   48  <--  A004779
    9|    9   18   19   25   36   37   38   39   41   50
   10|   10   20   21   26   40   41   42   43   52   53  <--  A132782
		

Crossrefs

Programs

  • Perl
    See Links section.

Formula

T(n, 1) = n.
T(n, 2) = 2*n.
T(n, 3) = 2*n + 1.
T(1, n) = A000027(n).
T(2, n) = A062289(n).
T(3, n) = A004780(n).
T(4, n) = A004753(n).
T(5, n) = A004748(n).
T(6, n) = A004749(n).
T(7, n) = A004781(n).
T(8, n) = A004779(n-1).
T(10, n) = A132782(n).
Previous Showing 11-12 of 12 results.