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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.

A257770 Table read by rows: numbers k, 0<=k<=9, such that n is a Belgian-k number.

Original entry on oeis.org

0, 0, 1, 0, 2, 0, 3, 0, 4, 0, 5, 0, 6, 0, 7, 0, 8, 0, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 2, 3, 5, 6, 8, 9, 0, 1, 4, 5, 8, 9, 3, 4, 8, 9, 2, 3, 8, 9, 1, 2, 8, 9, 0, 1, 8, 9, 0, 8, 9, 8, 9, 0, 2, 4, 6, 8, 0, 1, 3, 4, 6, 7, 9, 0
Offset: 0

Views

Author

Reinhard Zumkeller, May 08 2015

Keywords

Comments

See A106039 for definition of Belgian-k numbers;
T(n,0) = A257778(n); T(n,A257773(n)) = A257779(n);
m is a Belgian-0 number iff T(m,0) = 0.

Examples

			The first 100 rows:
.   0 | 0                     25 | 2,4,9       50 | 0,5     75 | 3,8
.   1 | 0,1                   26 | 0,2,8       51 | 3,4,9   76 | 4
.   2 | 0,2                   27 | 0,7,9       52 | 3,5     77 | 0,7
.   3 | 0,3                   28 | 6,8         53 | 0,5,8   78 | 3
.   4 | 0,4                   29 | 5,7         54 | 0,4,9   79 | 8
.   5 | 0,5                   30 | 0,3,6,9     55 | 0,5     80 | 0,8
.   6 | 0,6                   31 | 0,3,4,7,8   56 | 1,7     81 | 0,1,9
.   7 | 0,7                   32 | 2,4,7,9     57 | 4,9     82 | 2,4
.   8 | 0,8                   33 | 0,3,6,9     58 | 1,6     83 | 6,9
.   9 | 0,9                   34 | 3,6         59 | 3       84 | 0,4
.  10 | 0,1,2,3,4,5,6,7,8,9   35 | 0,3,8       60 | 0,6     85 | 7
.  11 | 0,1,2,3,4,5,6,7,8,9   36 | 0,6,9       61 | 5,6     86 | 2,8
.  12 | 0,2,3,5,6,8,9         37 | 4,7         62 | 0,6,8   87 | 4
.  13 | 0,1,4,5,8,9           38 | 2,5         63 | 0,3,9   88 | 0,8
.  14 | 3,4,8,9               39 | 0,3         64 | 4,8     89 | 4
.  15 | 2,3,8,9               40 | 0,4,8       65 | 4       90 | 0,9
.  16 | 1,2,8,9               41 | 1,2,6,7     66 | 0,6     91 | 1,2
.  17 | 0,1,8,9               42 | 0,2,6,8     67 | 2,9     92 | 4,6
.  18 | 0,8,9                 43 | 1,4,8       68 | 6       93 | 0,9
.  19 | 8,9                   44 | 0,4,8       69 | 3,9     94 | 3,7
.  20 | 0,2,4,6,8             45 | 0,5,9       70 | 0,7     95 | 2
.  21 | 0,1,3,4,6,7,9         46 | 2,6         71 | 0,7,8   96 | 6
.  22 | 0,2,4,6,8             47 | 3           72 | 0,2,9   97 | 1,8
.  23 | 1,3,6,8               48 | 0,8         73 | 3,6     98 | 4
.  24 | 0,4,6                 49 | 6           74 | 1,8     99 | 0,9  .
		

Crossrefs

Cf. A257773 (row lengths), A257778 (min per row), A257778 (max per row),

Programs

  • Haskell
    a257770 n k = a257770_tabf !! n !! k
    a257770_row n = filter belge [0..9] where
       belge k = n == (head $ dropWhile (< n) $
                      scanl (+) k $ cycle $ (map (read . return) . show) n)
    a257770_tabf = map a257770_row [0..]