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.

A342218 The n-th and a(n)-th points of the Peano curve (A163528, A163529) are symmetrical with respect to the line X=Y.

Original entry on oeis.org

0, 5, 6, 7, 4, 1, 2, 3, 8, 45, 50, 51, 52, 49, 46, 47, 48, 53, 54, 59, 60, 61, 58, 55, 56, 57, 62, 63, 68, 69, 70, 67, 64, 65, 66, 71, 36, 41, 42, 43, 40, 37, 38, 39, 44, 9, 14, 15, 16, 13, 10, 11, 12, 17, 18, 23, 24, 25, 22, 19, 20, 21, 26, 27, 32, 33, 34, 31
Offset: 0

Views

Author

Rémy Sigrist, Mar 05 2021

Keywords

Comments

In other words, a(n) is the unique k such that A163528(n) = A163529(k) and A163528(k) = A163529(n).
This sequence is a self-inverse permutation of the nonnegative integers.

Examples

			The Peano curve (A163528, A163529) begins as follows:
       +-----+-----+
       |6     7     8
       |
       +-----+-----+
        5     4    |3
                   |
       +-----+-----+
        0     1     2
- so a(0) = 0,
     a(1) = 5,
     a(2) = 6,
     a(3) = 7,
     a(4) = 4,
     a(8) = 8.

Links

Crossrefs

See A342217 and A342224 for similar sequences.
Cf. A163528, A163529, A338086.

Programs

  • PARI
    See Links section.
  • PARI
    my(table=[0,5,6,7,4,1,2,3,8]); a(n) = fromdigits(apply(d->table[d+1], digits(n,9)), 9); \\ Kevin Ryde, Mar 07 2021

Formula

a(n) = n iff n belongs to A338086.
a(n) < 9^k for any n < 9^k.

A342224 The n-th and a(n)-th points of the curve (A334474, A334475) are symmetrical with respect to the line X=Y.

Original entry on oeis.org

0, 2, 1, 3, 8, 9, 7, 6, 4, 5, 15, 11, 14, 13, 12, 10, 31, 32, 30, 29, 33, 35, 34, 28, 27, 26, 25, 24, 23, 19, 18, 16, 17, 20, 22, 21, 63, 62, 59, 58, 60, 61, 42, 44, 43, 47, 46, 45, 57, 55, 56, 51, 54, 53, 52, 49, 50, 48, 39, 38, 40, 41, 37, 36, 121, 122, 120
Offset: 0

Views

Author

Rémy Sigrist, Mar 06 2021

Keywords

Comments

In other words, a(n) is the unique k such that A334474(n) = A334475(k) and A334474(k) = A334475(n).
This sequence is a self-inverse permutation of the nonnegative integers.

Examples

			The curve (A334474, A334475) begins as follows on a hexagonal lattice:
                 +
                /5\
               /   \
              +4    +6
               \     \
                \     \
           +    3+     +7
          /1\   /     /
         /   \ /     /
        +     +     +----+
         0     2     8    9
- so a(0) = 0,
     a(1) = 2,
     a(3) = 3,
     a(4) = 8,
     a(5) = 9,
     a(6) = 7.

Links

Crossrefs

See A342217 and A342218 for similar sequences.
Cf. A007582, A334474, A334475.

Programs

  • PARI
    See Links section.

Formula

a(n) < A007582(k) for any n < A007582(k).
Showing 1-2 of 2 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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