A306993 Lexicographically earliest sequence of distinct positive terms such that for any n > 0, n * a(n) is digitally balanced.

2, 1, 3, 11, 7, 25, 5, 23, 15, 17, 4, 13, 12, 43, 9, 47, 10, 31, 29, 37, 34, 26, 8, 39, 6, 22, 30, 81, 19, 27, 18, 95, 63, 21, 61, 67, 20, 57, 24, 70, 56, 51, 14, 55, 49, 54, 16, 53, 45, 58, 42, 65, 48, 46, 44, 41, 38, 50, 62, 149, 35, 59, 33, 191, 52, 127, 36

Offset

1,1

Comments

Digitally balanced numbers correspond to A031443.

This sequence has similarities with A300868.

This sequence is a self-inverse permutation of the natural numbers.

Links

Rémy Sigrist, Table of n, a(n) for n = 1..10000

Rémy Sigrist, PARI program for A306993

Rémy Sigrist, Colored scatterplot of the first 10000 terms (where the color is function of A000120(n*a(n)))

Index entries for sequences that are permutations of the natural numbers

Example

The first terms, alongside the binary representation of n * a(n), are:
  n   a(n)  bin(n * a(n))
  --  ----  --------------
   1     2              10
   2     1              10
   3     3            1001
   4    11          101100
   5     7          100011
   6    25        10010110
   7     5          100011
   8    23        10111000
   9    15        10000111
  10    17        10101010
  11     4          101100
  12    13        10011100
  13    12        10011100
  14    43      1001011010
  15     9        10000111
  16    47      1011110000

Prog

(PARI) See Links section.

Crossrefs

Cf. A000120, A031443, A300868.

Sequence in context: A372523 A196371 A276116 * A119928 A215265 A036448

Adjacent sequences: A306990 A306991 A306992 * A306994 A306995 A306996

Keyword

nonn,look,base

Author

Rémy Sigrist, Mar 18 2019

Status

approved