A374791 Irregular triangle T(n, k), n >= 0, k = 1..A120880(n), read by rows; the n-th lists the integers m such that A374560(m) = n.

0, 1, 2, 4, 3, 5, 6, 7, 8, 9, 11, 13, 12, 17, 18, 24, 10, 14, 15, 16, 19, 20, 22, 26, 21, 23, 25, 27, 28, 29, 30, 31, 32, 33, 34, 35, 37, 39, 41, 43, 38, 42, 47, 48, 51, 52, 58, 62, 40, 49, 50, 60, 59, 61, 70, 71, 72, 73, 83, 85, 84, 97, 98, 112, 36, 44, 45, 46, 53, 54

Offset: 0

Author

Rémy Sigrist, Jul 20 2024

Keywords

• nonn
• tabf
• base

Comments

A374560 corresponds to a square array, but we consider it here as a flat sequence (when its values are read according along its antidiagonals).

As a flat sequence, this is a permutation of the nonnegative integers with inverse A374792.

Examples

			Triangle T(n, k) begins:
  n   n-th row
  --  ------------------------------
   0  0
   1  1, 2
   2  4
   3  3, 5
   4  6, 7, 8, 9
   5  11, 13
   6  12
   7  17, 18
   8  24
   9  10, 14
  10  15, 16, 19, 20
  11  22, 26
  12  21, 23, 25, 27
  13  28, 29, 30, 31, 32, 33, 34, 35
  14  37, 39, 41, 43
  15  38, 42
		

Links

• Rémy Sigrist, Table of n, a(n) for n = 0..8255
• Rémy Sigrist, PARI program
• Index entries for sequences that are permutations of the natural numbers

Crossrefs

Cf. A120880, A374560, A374792 (inverse).

Programs

PARI

\\ See Links section.