cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A262437 Triangle T(n,k): write n in base 16, reverse order of digits.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 0, 1, 1, 1, 2, 1, 3, 1, 4, 1, 5, 1, 6, 1, 7, 1, 8, 1, 9, 1, 10, 1, 11, 1, 12, 1, 13, 1, 14, 1, 15, 1, 0, 2, 1, 2, 2, 2, 3, 2, 4, 2, 5, 2, 6, 2, 7, 2, 8, 2, 9, 2, 10, 2, 11, 2, 12, 2, 13, 2, 14, 2, 15, 2
Offset: 0

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Author

Reinhard Zumkeller, Sep 22 2015

Keywords

Comments

Sum(T(n,k)*16^k : k = 0..A262438(n)-1) = n.

Examples

			.   n | HEX | T(n,*)        n | HEX | T(n,*)        n | HEX | T(n,*)
. ----+-----+--------     ----+-----+--------     ----+-----+--------
.   0 |   0 |  [0]         24 |  18 |  [8,1]       48 |  30 |  [0,3]
.   1 |   1 |  [1]         25 |  19 |  [9,1]       49 |  31 |  [1,3]
.   2 |   2 |  [2]         26 |  1A |  [10,1]      50 |  32 |  [2,3]
.   3 |   3 |  [3]         27 |  1B |  [11,1]      51 |  33 |  [3,3]
.   4 |   4 |  [4]         28 |  1C |  [12,1]      52 |  34 |  [4,3]
.   5 |   5 |  [5]         29 |  1D |  [13,1]      53 |  35 |  [5,3]
.   6 |   6 |  [6]         30 |  1E |  [14,1]      54 |  36 |  [6,3]
.   7 |   7 |  [7]         31 |  1F |  [15,1]      55 |  37 |  [7,3]
.   8 |   8 |  [8]         32 |  20 |  [0,2]       56 |  38 |  [8,3]
.   9 |   9 |  [9]         33 |  21 |  [1,2]       57 |  39 |  [9,3]
.  10 |   A |  [10]        34 |  22 |  [2,2]       58 |  3A |  [10,3]
.  11 |   B |  [11]        35 |  23 |  [3,2]       59 |  3B |  [11,3]
.  12 |   C |  [12]        36 |  24 |  [4,2]       60 |  3C |  [12,3]
.  13 |   D |  [13]        37 |  25 |  [5,2]       61 |  3D |  [13,3]
.  14 |   E |  [14]        38 |  26 |  [6,2]       62 |  3E |  [14,3]
.  15 |   F |  [15]        39 |  27 |  [7,2]       63 |  3F |  [15,3]
.  16 |  10 |  [0,1]       40 |  28 |  [8,2]       64 |  40 |  [0,4]
.  17 |  11 |  [1,1]       41 |  29 |  [9,2]       65 |  41 |  [1,4]
.  18 |  12 |  [2,1]       42 |  2A |  [10,2]      66 |  42 |  [2,4]
.  19 |  13 |  [3,1]       43 |  2B |  [11,2]      67 |  43 |  [3,4]
.  20 |  14 |  [4,1]       44 |  2C |  [12,2]      68 |  44 |  [4,4]
.  21 |  15 |  [5,1]       45 |  2D |  [13,2]      69 |  45 |  [5,4]
.  22 |  16 |  [6,1]       46 |  2E |  [14,2]      70 |  46 |  [6,4]
.  23 |  17 |  [7,1]       47 |  2F |  [15,2]      71 |  47 |  [7,4]
.  24 |  18 |  [8,1]       48 |  30 |  [0,3]       72 |  48 |  [8,4]  .
		

Crossrefs

Cf. A001025, A262438 (row lengths), A030308 (binary), A030341 (ternary), A031298 (decimal).

Programs

  • Haskell
    a262437 n k = a262437_tabf !! n !! k
    a262437_row n = a262437_tabf !! n
    a262437_tabf = iterate succ [0] where
       succ []      = [1]
       succ (15:hs) = 0 : succ hs
       succ (h:hs)  = (h + 1) : hs