A375376 Square array read by antidiagonals: Let n = Sum_{i=1..m} 2^e_i be the binary expansion of n, let S be the set {e_i+2; 1 <= i <= m}, and let X be the sequence of power towers built of numbers in S, sorted first by their height and then colexicographically. The n-th row of the array gives the permutation of indices which reorders X by magnitude. In case of ties, keep the colexicographic order.

1, 2, 1, 3, 2, 1, 4, 3, 2, 1, 5, 4, 3, 2, 1, 6, 5, 5, 3, 2, 1, 7, 6, 4, 4, 3, 2, 1, 8, 7, 7, 5, 4, 3, 2, 1, 9, 8, 6, 6, 5, 4, 3, 2, 1, 10, 9, 8, 7, 7, 5, 4, 3, 3, 1, 11, 10, 11, 8, 6, 6, 7, 4, 2, 2, 1, 12, 11, 9, 9, 8, 7, 5, 5, 7, 3, 2, 1, 13, 12, 12, 10, 9, 8, 6, 6, 4, 4, 4, 2, 1

Offset

1,2

Comments

Each row is a permutation of the positive integers.

If n is a power of 2, the set S contains a single number and the n-th row is the identity permutation.

Links

Table of n, a(n) for n=1..91.

Index entries for sequences that are permutations of the natural numbers.

Example

Array begins:
   n=1: 1, 2, 3, 4, 5, 6,  7,  8,  9, 10, 11, 12, 13, 14, 15, ...
   n=2: 1, 2, 3, 4, 5, 6,  7,  8,  9, 10, 11, 12, 13, 14, 15, ...
   n=3: 1, 2, 3, 5, 4, 7,  6,  8, 11,  9, 12, 10, 15, 16, 13, ...
   n=4: 1, 2, 3, 4, 5, 6,  7,  8,  9, 10, 11, 12, 13, 14, 15, ...
   n=5: 1, 2, 3, 4, 5, 7,  6,  8,  9, 11, 15, 10, 12, 16, 13, ...
   n=6: 1, 2, 3, 4, 5, 6,  7,  8,  9, 10, 11, 12, 13, 14, 15, ...
   n=7: 1, 2, 3, 4, 7, 5,  6, 10, 13,  8,  9, 11, 14, 12, 15, ...
   n=8: 1, 2, 3, 4, 5, 6,  7,  8,  9, 10, 11, 12, 13, 14, 15, ...
   n=9: 1, 3, 2, 7, 4, 5,  8,  6, 15,  9, 11, 16, 10, 12, 17, ...
  n=10: 1, 2, 3, 4, 5, 6,  7,  8,  9, 10, 11, 12, 13, 14, 15, ...
  n=11: 1, 2, 4, 3, 7, 5, 13,  6,  8, 10, 14,  9, 11, 22, 16, ...
  n=12: 1, 2, 3, 4, 5, 6,  7,  8,  9, 10, 11, 12, 13, 14, 15, ...
  n=13: 1, 2, 4, 3, 5, 7, 13,  6, 10,  8, 14,  9, 15, 11, 12, ...
  n=14: 1, 2, 3, 4, 5, 7,  6, 10,  8,  9, 11, 12, 13, 14, 15, ...
  n=15: 1, 2, 3, 5, 4, 9,  6,  7, 13, 21,  8, 10, 17, 11, 14, ...
For n = 7 = 2^0 + 2^1 + 2^2, the set S is {0+2, 1+2, 2+2} = {2, 3, 4}. The smallest power towers formed by 2's, 3's, and 4's, together with their colex ranks are:
   k | power tower | colex rank T(7,k)
   --+-------------+------------------
   1 |     2 = 2   |        1
   2 |     3 = 3   |        2
   3 |     4 = 4   |        3
   4 |   2^2 = 4   |        4
   5 |   2^3 = 8   |        7
   6 |   3^2 = 9   |        5
   7 |   4^2 = 16  |        6
   8 |   2^4 = 16  |       10
   9 | 2^2^2 = 16  |       13
  10 |   3^3 = 27  |        8
  11 |   4^3 = 64  |        9
  12 |   3^4 = 81  |       11
  13 | 3^2^2 = 81  |       14
  14 |   4^4 = 256 |       12
  15 | 4^2^2 = 256 |       15

Crossrefs

Cf. A185969, A299229, A375374 (3rd row), A375377 (the inverse permutation to each row).

Sequence in context: A200329 A023122 A375377 * A200272 A167286 A249821

Adjacent sequences: A375373 A375374 A375375 * A375377 A375378 A375379

Keyword

nonn,tabl

Author

Pontus von Brömssen, Aug 14 2024

Status

approved