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.

Showing 1-7 of 7 results.

A109681 "Sloping ternary numbers": write numbers in ternary under each other (right-justified), read diagonals in upward direction, convert to decimal.

Original entry on oeis.org

0, 1, 5, 3, 4, 8, 6, 16, 11, 9, 10, 14, 12, 13, 17, 15, 25, 20, 18, 19, 23, 21, 22, 26, 51, 34, 29, 27, 28, 32, 30, 31, 35, 33, 43, 38, 36, 37, 41, 39, 40, 44, 42, 52, 47, 45, 46, 50, 48, 49, 53, 78, 61, 56, 54, 55, 59, 57, 58, 62, 60, 70, 65, 63, 64, 68, 66
Offset: 0

Views

Author

Philippe Deléham, Aug 08 2005

Keywords

Comments

All terms are distinct, but certain terms (see A109682) are missing.
For the terms 3^k-1 (all 2's in ternary), the diagonal is not started at the leading 2, but at the leading 1 of the following term. - Georg Fischer, Mar 13 2020

Examples

			number diagonal decimal
    0      0     0
    1      1     1
    2     12     5
   10     10     3
   11     11     4
   12     22     8
   20     20     6
   21    121    16
   22    102    11
  100    100     9
  101    101    10
  102    112    14
  110    110    12
  11.    ...   ...
  1.
  .
		

Crossrefs

Cf. A109682 (complement), A109683 (ternary version), A109684.
Cf. A102370 (base 2), A325644 (base 4), A325645 (base 5), A325692 (base 6), A325693 (base 7), A325805 (base 8), A325829 (base 9), A103205 (base 10).
Cf. A030341.

Programs

  • Haskell
    a109681 n = a109681_list !! n
    a109681_list = map (foldr (\d v -> 3 * v + d) 0) $ f a030341_tabf where
       f vss = (g 0 vss) : f (tail vss)
       g k (ws:wss) = if k < length ws then ws !! k : g (k + 1) wss else []
    -- Reinhard Zumkeller, Nov 19 2013
    
  • Maple
    t:= (n, i)-> (d-> `if`(i=0, d, t(m, i-1)))(irem(n, 3, 'm')):
    b:= (n, i)-> `if`(3^i>n, 0, t(n,i) +3*b(n+1, i+1)):
    a:= n-> b(n, 0):
    seq(a(n), n=0..100);  # Alois P. Heinz, Mar 13 2020
  • Perl
    Cf. link.

Extensions

Conjectured g.f. and recurrence removed by Georg Fischer, Mar 13 2020

A103205 Write numbers in decimal under each other, then read diagonals in upward direction.

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Mar 27 2005

Keywords

Comments

Decimal analog of A102370.

Crossrefs

Cf. A102370 (base 2), A109681 (base 3), A325644 (base 4), A325645 (base 5), A325692 (base 6), A325693 (base 7), A325805 (base 8), A325829 (base 9), this sequence (base 10).

A325644 "Sloping quaternary numbers": write numbers in quaternary under each other (right-justified), read diagonals in upward direction, convert to decimal.

Original entry on oeis.org

0, 1, 2, 7, 4, 5, 6, 11, 8, 9, 10, 15, 12, 13, 30, 19, 16, 17, 18, 23, 20, 21, 22, 27, 24, 25, 26, 31, 28, 29, 46, 35, 32, 33, 34, 39, 36, 37, 38, 43, 40, 41, 42, 47, 44, 45, 62, 51, 48, 49, 50, 55, 52, 53, 54, 59, 56, 57, 58, 63, 60, 125, 78, 67, 64, 65, 66, 71, 68, 69, 70
Offset: 0

Views

Author

Seiichi Manyama, Sep 07 2019

Keywords

Examples

			    0
    1
    2
    3
   10
   11
   12
   13
   20
   21
   22
   23
   30
   31
   32
   33
  100
...
The upward-sloping diagonals are:
0
1
2
13
10
11
12
23
20
21
22
33
30
31
132
103
100
...
giving 0, 1, 2, "7", 4, 5, 6, "11", 8, 9, 10, "15", 12, 13, "30", "19", 16, ...
		

Crossrefs

Cf. A102370 (base 2), A109681 (base3), this sequence (base 4), A325645 (base 5), A325692 (base 6), A325693 (base 7), A325805 (base 8), A325829 (base 9), A103205 (base 10).

Programs

  • Ruby
    def A(m, n)
      ary = [0]
      n.times{|i|
        (m ** i - i..m ** (i + 1) - i - 2).each{|j|
          ary << (0..i).inject(0){|s, k| s + (j + k).to_s(m)[-1 - k].to_i * m ** k}
        }
      }
      ary
    end
    p A(4, 4)

A325645 "Sloping quinary numbers": write numbers in quinary under each other (right-justified), read diagonals in upward direction, convert to decimal.

Original entry on oeis.org

0, 1, 2, 3, 9, 5, 6, 7, 8, 14, 10, 11, 12, 13, 19, 15, 16, 17, 18, 24, 20, 21, 22, 48, 29, 25, 26, 27, 28, 34, 30, 31, 32, 33, 39, 35, 36, 37, 38, 44, 40, 41, 42, 43, 49, 45, 46, 47, 73, 54, 50, 51, 52, 53, 59, 55, 56, 57, 58, 64, 60, 61, 62, 63, 69, 65, 66, 67, 68, 74, 70, 71
Offset: 0

Views

Author

Seiichi Manyama, Sep 07 2019

Keywords

Crossrefs

Cf. A102370 (base 2), A109681 (base3), A325644 (base 4), this sequence (base 5), A325692 (base 6), A325693 (base 7), A325805 (base 8), A325829 (base 9), A103205 (base 10).

Programs

  • Ruby
    def A(m, n)
      ary = [0]
      n.times{|i|
        (m ** i - i..m ** (i + 1) - i - 2).each{|j|
          ary << (0..i).inject(0){|s, k| s + (j + k).to_s(m)[-1 - k].to_i * m ** k}
        }
      }
      ary
    end
    p A(5, 3)

A325692 "Sloping senary numbers": write numbers in senary (that is, base 6) under each other (right-justified), read diagonals in upward direction, convert to decimal.

Original entry on oeis.org

0, 1, 2, 3, 4, 11, 6, 7, 8, 9, 10, 17, 12, 13, 14, 15, 16, 23, 18, 19, 20, 21, 22, 29, 24, 25, 26, 27, 28, 35, 30, 31, 32, 33, 70, 41, 36, 37, 38, 39, 40, 47, 42, 43, 44, 45, 46, 53, 48, 49, 50, 51, 52, 59, 54, 55, 56, 57, 58, 65, 60, 61, 62, 63, 64, 71, 66, 67, 68, 69, 106, 77, 72
Offset: 0

Views

Author

Seiichi Manyama, Sep 07 2019

Keywords

Crossrefs

Cf. A102370 (base 2), A109681 (base 3), A325644 (base 4), A325645 (base 5), this sequence (base 6), A325693 (base 7), A325805 (base 8), A325829 (base 9), A103205 (base 10).

A325693 "Sloping septenary numbers": write numbers in septenary under each other (right-justified), read diagonals in upward direction, convert to decimal.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 13, 7, 8, 9, 10, 11, 12, 20, 14, 15, 16, 17, 18, 19, 27, 21, 22, 23, 24, 25, 26, 34, 28, 29, 30, 31, 32, 33, 41, 35, 36, 37, 38, 39, 40, 48, 42, 43, 44, 45, 46, 96, 55, 49, 50, 51, 52, 53, 54, 62, 56, 57, 58, 59, 60, 61, 69, 63, 64, 65, 66, 67, 68, 76, 70, 71
Offset: 0

Views

Author

Seiichi Manyama, Sep 07 2019

Keywords

Crossrefs

Cf. A102370 (base 2), A109681 (base 3), A325644 (base 4), A325645 (base 5), A325692 (base 6), this sequence (base 7), A325805 (base 8), A325829 (base 9), A103205 (base 10).

A325805 "Sloping octal numbers": write numbers in octal under each other (right-justified), read diagonals in upward direction, convert to decimal.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 15, 8, 9, 10, 11, 12, 13, 14, 23, 16, 17, 18, 19, 20, 21, 22, 31, 24, 25, 26, 27, 28, 29, 30, 39, 32, 33, 34, 35, 36, 37, 38, 47, 40, 41, 42, 43, 44, 45, 46, 55, 48, 49, 50, 51, 52, 53, 54, 63, 56, 57, 58, 59, 60, 61, 126, 71, 64, 65, 66, 67, 68, 69, 70, 79
Offset: 0

Views

Author

Seiichi Manyama, Sep 07 2019

Keywords

Crossrefs

Cf. A102370 (base 2), A109681 (base 3), A325644 (base 4), A325645 (base 5), A325692 (base 6), A325693 (base 7), this sequence (base 8), A325829 (base 9), A103205 (base 10).
Showing 1-7 of 7 results.