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 1-10 of 16 results. Next

A163912 Least common multiple of all cycle sizes in range [A000302(n-1)..A024036(n)] of permutation A163355/A163356.

Original entry on oeis.org

1, 2, 6, 24, 36, 288, 432, 1728, 2592, 31104, 15552
Offset: 0

Views

Author

Antti Karttunen, Sep 19 2009

Keywords

Crossrefs

A163910 Number of cycles in range [A000302(n-1)..A024036(n)] of permutation A163355/A163356.

Original entry on oeis.org

1, 2, 3, 18, 30, 178, 306, 1864, 3214, 20032, 34708
Offset: 0

Views

Author

Antti Karttunen, Sep 19 2009

Keywords

Crossrefs

A163911 Maximum cycle size in range [A000302(n-1)..A024036(n)] of permutation A163355/A163356.

Original entry on oeis.org

1, 2, 6, 8, 18, 32, 108, 216, 324, 1944, 1944
Offset: 0

Views

Author

Antti Karttunen, Sep 19 2009

Keywords

Crossrefs

A163914 Number of 3-cycles in range [A000302(n-1)..A024036(n)] of permutation A163355/A163356.

Original entry on oeis.org

0, 0, 2, 1, 10, 9, 54, 57, 295, 329, 1613, 1834, 8812, 10072
Offset: 0

Views

Author

Antti Karttunen, Sep 19 2009

Keywords

Crossrefs

a(n) = A163913(n)/3. Bisections: A163909, A163919. See also A163903, A163911, A163912, A163904, A163890.

A163906 Permutation A163356 applied twice.

Original entry on oeis.org

0, 1, 2, 3, 12, 15, 13, 14, 7, 4, 5, 6, 9, 11, 8, 10, 16, 19, 17, 18, 20, 21, 22, 23, 27, 25, 26, 24, 30, 29, 28, 31, 47, 44, 45, 46, 39, 37, 38, 36, 40, 41, 42, 43, 34, 33, 35, 32, 58, 56, 59, 57, 54, 53, 52, 55, 49, 50, 48, 51, 60, 61, 62, 63, 192, 195, 193, 194, 196, 197
Offset: 0

Views

Author

Antti Karttunen, Sep 19 2009

Keywords

Crossrefs

Inverse: A163905. a(n) = A163356(A163356(n)). See also A163916.

A163916 Permutation A163356 applied thrice.

Original entry on oeis.org

0, 1, 3, 2, 7, 5, 6, 4, 9, 8, 10, 11, 14, 13, 12, 15, 16, 17, 18, 19, 20, 21, 23, 22, 30, 29, 31, 28, 24, 25, 27, 26, 58, 59, 57, 56, 54, 53, 55, 52, 60, 61, 63, 62, 51, 50, 49, 48, 32, 35, 34, 33, 36, 37, 39, 38, 46, 44, 47, 45, 40, 41, 43, 42, 127, 125, 126, 124, 119, 117
Offset: 0

Views

Author

Antti Karttunen, Sep 19 2009

Keywords

Crossrefs

Inverse: A163915. Cf. A163356, A163906.

Formula

A302844 Permutation of nonnegative integers: a(n) = A003188(A163356(n)).

Original entry on oeis.org

0, 1, 2, 3, 12, 15, 14, 13, 10, 9, 8, 11, 4, 5, 6, 7, 24, 27, 26, 25, 30, 31, 28, 29, 18, 19, 16, 17, 22, 21, 20, 23, 40, 43, 42, 41, 46, 47, 44, 45, 34, 35, 32, 33, 38, 37, 36, 39, 56, 57, 58, 59, 52, 55, 54, 53, 50, 49, 48, 51, 60, 61, 62, 63, 192, 195, 194, 193, 198, 199, 196, 197, 202, 203, 200, 201, 206, 205
Offset: 0

Views

Author

Antti Karttunen, Apr 14 2018

Keywords

Comments

When A207901, which is a multiplicative walk permutation, is composed from the right with this permutation, the result is A302781, another multiplicative walk permutation.

Crossrefs

Programs

Formula

a(n) = A003188(A163356(n)).
a(n) = A006068(A302846(n)).

A163913 Number of integers i in range [A000302(n-1)..A024036(n)] of permutation A163355/A163356 with A163915(i)=i, but not A163355(i)=i.

Original entry on oeis.org

0, 0, 6, 3, 30, 27, 162, 171, 885, 987, 4839, 5502, 26436, 30216
Offset: 0

Views

Author

Antti Karttunen, Sep 19 2009

Keywords

Crossrefs

a(n) = 3*A163914(n). See also A163903.

A163355 Permutation of integers for constructing Hilbert curve in N x N grid.

Original entry on oeis.org

0, 1, 3, 2, 14, 15, 13, 12, 4, 7, 5, 6, 8, 11, 9, 10, 16, 19, 17, 18, 20, 21, 23, 22, 30, 29, 31, 28, 24, 25, 27, 26, 58, 57, 59, 56, 54, 53, 55, 52, 60, 61, 63, 62, 50, 51, 49, 48, 32, 35, 33, 34, 36, 37, 39, 38, 46, 45, 47, 44, 40, 41, 43, 42, 234, 235, 233, 232, 236, 239
Offset: 0

Views

Author

Antti Karttunen, Jul 29 2009

Keywords

Crossrefs

Inverse: A163356. A163357 & A163359 give two variants of Hilbert curve in N x N grid. Cf. also A163332.
Second and third "powers": A163905, A163915.
In range [A000302(n-1)..A024036(n)] of this permutation, the number of cycles is given by A163910, number of fixed points seems to be given by A147600(n-1) (fixed points themselves: A163901). Max. cycle sizes is given by A163911 and LCM's of all cycle sizes by A163912.

Programs

  • Maple
    A057300 := proc(n)
        option remember;
        `if`(n=0, 0, procname(iquo(n, 4, 'r'))*4+[0, 2, 1, 3][r+1])
    end proc:
    A163355 := proc(n)
        option remember ;
        local d,base4,i,r ;
        if n <= 1 then
            return n ;
        end if;
        base4 := convert(n,base,4) ;
        d := op(-1,base4) ;
        i := nops(base4)-1 ;
        r := n-d*4^i ;
        if ( d=1 and type(i,even) ) or ( d=2 and type(i,odd)) then
            4^i+procname(A057300(r)) ;
        elif d= 3 then
            2*4^i+procname(A057300(r)) ;
        else
            3*4^i+procname(4^i-1-r) ;
        end if;
    end proc:
    seq(A163355(n),n=0..100) ; # R. J. Mathar, Nov 22 2023
  • PARI
    A057300(n) = { my(t=1, s=0); while(n>0,  if(1==(n%4),n++,if(2==(n%4),n--)); s += (n%4)*t; n >>= 2; t <<= 2); (s); };
    A163355(n) = if(!n,n,my(i = (#binary(n)-1)\2, f = 4^i, d = (n\f)%4, r = (n%f)); if(((1==d)&&!(i%2))||((2==d)&&(i%2)), f+A163355(A057300(r)), if(3==d,f+f+A163355(A057300(r)), (3*f)+A163355(f-1-r)))); \\ Antti Karttunen, Apr 14 2018

Formula

a(0) = 0, and given d=1, 2 or 3, then a((d*(4^i))+r)
= (4^i) + a(A057300(r)), if d=1 and i is even, or if d=2 and i is odd
= 2*(4^i) + a(A057300(r)), if d=3,
= 3*(4^i) + a((4^i)-1-r) in other cases.
From Alan Michael Gómez Calderón, May 06 2025: (Start)
a(3*A000695(n)) = 2*A000695(n);
a(3*(A000695(n) + 2^A000695(2*m))) = 2*(A000695(n) + 2^A000695(2*m)) for m >= 2;
a((2 + 16^n)*2^(-1 + 4*m)) = 4^(2*(n + m) - 1) + (11*16^m - 2)/3. (End)

Extensions

Links to further derived sequences added by Antti Karttunen, Sep 21 2009

A059252 Hilbert's Hamiltonian walk on N X N projected onto x axis: m(3).

Original entry on oeis.org

0, 0, 1, 1, 2, 3, 3, 2, 2, 3, 3, 2, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, 1, 2, 2, 3, 3, 3, 2, 2, 3, 4, 5, 5, 4, 4, 4, 5, 5, 6, 6, 7, 7, 7, 6, 6, 7, 7, 7, 6, 6, 5, 4, 4, 5, 5, 4, 4, 5, 6, 6, 7, 7, 8, 9, 9, 8, 8, 8, 9, 9, 10, 10, 11, 11, 11, 10, 10, 11, 12, 12, 13, 13, 14, 15, 15, 14, 14, 15, 15, 14
Offset: 0

Views

Author

Claude Lenormand (claude.lenormand(AT)free.fr), Jan 23 2001

Keywords

Comments

This is the X-coordinate of the n-th term in Hilbert's Hamiltonian walk A163359 and the Y-coordinate of its transpose A163357.

Examples

			[m(1)=0 0 1 1, m'(1)= 0 1 10] [m(2) =0 0 1 1 2 3 3 2 2 3 3 2 1 1 0 0, m'(2)=0 1 1 0 0 0 1 1 2 2 3 3 3 2 2 3].
		

Crossrefs

See also the y-projection, m'(3), A059253, as well as: A163539, A163540, A163542, A059261, A059285, A163547 and A163529.

Programs

  • C
    void h(unsigned int *x, unsigned int *y, unsigned int l){
    x[0] = y[0] = 0; unsigned int *t = NULL; unsigned int n = 0, k = 0;
    for(unsigned int i = 1; i>(2*n)){
    case 1: x[i] = y[i&k]; y[i] = x[i&k]+(1<Jared Rager, Jan 09 2021 */
    (C++) See Fxtbook link.

Formula

Initially [m(0) = 0, m'(0) = 0]; recursion: m(2n + 1) = m(2n).m'(2n).f(m'(2n), 2n).c(m(2n), 2n + 1); m'(2n + 1) = m'(2n).f(m(2n), 2n).f(m(2n), 2n).mir(m'(2n)); m(2n) = m(2n - 1).f(m'(2n - 1), 2n - 1).f(m'(2n - 1), 2n - 1).mir(m(2n - 1)); m'(2n) = m'(2n - 1).m(2n - 1).f(m(2n - 1), 2n - 1).c(m'(2n - 1), 2n); where f(m, n) is the alphabetic morphism i := i + 2^n [example: f(0 0 1 1 2 3 3 2 2 3 3 2 1 1 0 0, 2) = 4 4 5 5 6 7 7 6 6 7 7 6 5 5 4 4]; c(m, n) is the complementation to 2^n - 1 alphabetic morphism [example: c(0 0 1 1 2 3 3 2 2 3 3 2 1 1 0 0, 3) = 7 7 6 6 5 4 4 5 5 4 4 5 6 6 7 7]; and mir(m) is the mirror operator [example: mir(0 1 1 0 0 0 1 1 2 2 3 3 3 2 2 3) = 3 2 2 3 3 3 2 2 1 1 0 0 0 1 1 0].
a(n) = A002262(A163358(n)) = A025581(A163360(n)) = A059906(A163356(n)).

Extensions

Extended by Antti Karttunen, Aug 01 2009
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