A371265 Irregular triangle T(n, k), n >= 0, read by rows; the n-th row lists the numbers m such that A371263(m) = n.

0, 1, 2, 3, 4, 5, 9, 6, 7, 8, 10, 11, 12, 13, 14, 27, 15, 16, 26, 28, 17, 19, 20, 21, 24, 25, 29, 30, 18, 22, 23, 31, 32, 36, 33, 34, 35, 37, 38, 39, 40, 41, 81, 42, 43, 80, 82, 44, 46, 47, 48, 78, 79, 83, 84, 45, 49, 77, 85, 50, 58, 59, 63, 72, 76, 86, 90

Offset: 0

Author

Rémy Sigrist, Mar 16 2024

Keywords

• nonn
• base
• tabf

Comments

Row 0 has 1 term; for n > 0, row n has A225081(n-1) terms.

As a flat sequence, this is a permutation of the nonnegative integers, with inverse A371266.

Examples

			Triangle T(n, k) begins:
  n   n-th row
  --  ------------------------------
   0  0
   1  1
   2  2, 3
   3  4
   4  5, 9
   5  6, 7, 8, 10
   6  11, 12
   7  13
   8  14, 27
   9  15, 16, 26, 28
  10  17, 19, 20, 21, 24, 25, 29, 30
  11  18, 22, 23, 31
  12  32, 36
  13  33, 34, 35, 37
  14  38, 39
  15  40
.
Triangle T(n, k) begins, in balanced ternary, with row indexes in binary:
  bin(n)  n-th row in balanced ternary
  ------  ----------------------------------------------
       0  0
       1  1
      10  1T, 10
      11  11
     100  1TT, 100
     101  1T0, 1T1, 10T, 101
     110  11T, 110
     111  111
    1000  1TTT, 1000
    1001  1TT0, 1TT1, 100T, 1001
    1010  1T0T, 1T01, 1T1T, 1T10, 10T0, 10T1, 101T, 1010
    1011  1T00, 1T11, 10TT, 1011
    1100  11TT, 1100
    1101  11T0, 11T1, 110T, 1101
    1110  111T, 1110
    1111  1111
		

Links

• Rémy Sigrist, Table of n, a(n) for n = 0..9841
• Rémy Sigrist, PARI program
• Index entries for sequences that are permutations of the natural numbers

Crossrefs

See A371257 for a similar sequence.

Cf. A225081, A371266 (inverse).

Programs

PARI

\\ See Links section.