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.

A360413 Irregular table T(n, k), n >= 0, k = 1..A002487(n+1), read by rows; the n-th row lists the numbers k such that A065361(k) = n.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 9, 7, 10, 8, 11, 12, 13, 14, 15, 18, 27, 16, 19, 28, 17, 20, 21, 29, 30, 22, 31, 23, 24, 32, 33, 36, 25, 34, 37, 26, 35, 38, 39, 40, 41, 42, 45, 54, 81, 43, 46, 55, 82, 44, 47, 48, 56, 57, 83, 84, 49, 58, 85, 50, 51, 59, 60, 63, 86, 87, 90
Offset: 0

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Author

Rémy Sigrist, Feb 06 2023

Keywords

Comments

As a flat sequence, this is a permutation of the nonnegative integers with inverse A360414.

Examples

			Table T(n, k) begins:
  n   n-th row
  --  ------------------
   0  0
   1  1
   2  2, 3
   3  4
   4  5, 6, 9
   5  7, 10
   6  8, 11, 12
   7  13
   8  14, 15, 18, 27
   9  16, 19, 28
  10  17, 20, 21, 29, 30
  11  22, 31
  12  23, 24, 32, 33, 36
.
Table T(n, k) begins (with terms given in base 3):
  n   n-th row in base 3
  --  -------------------------
   0  0
   1  1
   2  2, 10
   3  11
   4  12, 20, 100
   5  21, 101
   6  22, 102, 110
   7  111
   8  112, 120, 200, 1000
   9  121, 201, 1001
  10  122, 202, 210, 1002, 1010
  11  211, 1011
  12  212, 220, 1012, 1020, 1100
		

Crossrefs

Programs

  • PARI
    See Links section.

Formula

T(n, 1) = A032924(n) for any n > 0.
T(n, A002487(n+1)) = A005836(n+1).
A065361(T(n, k)) = n.