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.

Showing 1-2 of 2 results.

A336953 In binary representation, rotate the digits of n right n places.

Original entry on oeis.org

0, 1, 2, 3, 2, 3, 6, 7, 8, 12, 10, 7, 12, 14, 11, 15, 8, 12, 10, 7, 20, 26, 21, 30, 17, 25, 13, 30, 19, 27, 30, 31, 8, 12, 10, 7, 36, 50, 41, 60, 34, 19, 42, 53, 11, 45, 58, 31, 48, 56, 44, 30, 19, 43, 54, 59, 14, 15, 43, 55, 60, 62, 47, 63, 32, 48, 40, 28
Offset: 0

Views

Author

Gage Schacher, Aug 08 2020

Keywords

Comments

On the graph, there are a series of larger and larger parallelograms joined together by a straight line on y=x where n is unchanged, mostly in the case where n is a multiple of the bit length of n. In addition to the main line that cuts through the graph, each parallelogram has the same few sloped lines in its borders.

Examples

			a(3) = a('11') = '11' = 3;
a(4) = a('100') = '010' = '10' = 2;
a(5) = a('101') = '011' = '11' = 3;
		

Crossrefs

Cf. A007088, A038572 (rotated one binary place to the right).
Cf. A366139 (rotate left), A366140 (fixed points).

Programs

  • Mathematica
    Array[FromDigits[RotateRight[IntegerDigits[#, 2], #], 2] &, 68, 0] (* Michael De Vlieger, Oct 05 2020 *)
  • PARI
    a(n) = my(d=binary(n)); for (k=1, n, d = concat(d[#d], d[1..#d-1])); fromdigits(d, 2); \\ Michel Marcus, Aug 09 2020
    
  • Python
    def A336953(n):
        if n == 0: return 0
        l, m = -(n%n.bit_length()), bin(n)[2:]
        return int(m[l:]+m[:l],2) # Chai Wah Wu, Jan 22 2023

A366139 In binary representation, rotate the digits of n left n places.

Original entry on oeis.org

0, 1, 2, 3, 1, 6, 6, 7, 8, 3, 10, 13, 12, 11, 11, 15, 1, 6, 20, 25, 20, 11, 26, 29, 12, 25, 21, 15, 7, 30, 30, 31, 2, 12, 40, 49, 36, 11, 26, 60, 10, 52, 42, 23, 50, 45, 43, 55, 48, 35, 11, 30, 13, 58, 54, 47, 35, 15, 46, 61, 60, 59, 59, 63, 1, 6, 20, 56, 17, 98
Offset: 0

Views

Author

Paolo Xausa, Sep 30 2023

Keywords

Examples

			a(4) = 1 because 4 in base 2 is 100 and 100 rotated left 4 times is 100 -> 001 -> 010 -> 100 -> 001 = 1.
a(5) = 6 because 5 in base 2 is 101 and 101 rotated left 5 times is 101 -> 011 -> 110 -> 101 -> 011 -> 110 = 6 in base 10.
		

Crossrefs

Cf. A006257, A007088, A366140 (fixed points).
Cf. A336953 (rotate right).

Programs

  • Mathematica
    A366139[n_]:=FromDigits[RotateLeft[IntegerDigits[n,2],n],2];
    Array[A366139,100,0]
  • Python
    def A366139(n): return int((s:=bin(n))[(m:=n%n.bit_length()+2):]+s[2:m],2) if n else 0 # Chai Wah Wu, Oct 03 2023
Showing 1-2 of 2 results.