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

0,3

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.

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

Example

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

Prog

(PARI) \\ See Links section.

Crossrefs

See A371257 for a similar sequence.

Cf. A225081, A371266 (inverse).

Sequence in context: A289081 A105950 A227778 * A166276 A374950 A101544

Adjacent sequences: A371262 A371263 A371264 * A371266 A371267 A371268

Keyword

nonn,base,tabf

Author

Rémy Sigrist, Mar 16 2024

Status

approved