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 1-9 of 9 results.

A109682 Numbers missing from A109681.

Original entry on oeis.org

2, 7, 24, 80, 238, 723, 2183, 5653, 19674, 59042, 177145, 531429, 1594313, 4782955, 14348892, 43046708, 129140146, 387420471, 1162261451, 3486784397, 10460353182, 31381059590, 94143178804, 282429536457, 847288609421
Offset: 1

Views

Author

Philippe Deléham, Aug 08 2005

Keywords

Comments

3^(n-1) < a(n) < 3^n. - Reinhard Zumkeller, Nov 19 2013

Crossrefs

Cf. A109681, A109683, also A109684 (ternary equivalents).

Programs

  • Haskell
    -- import Data.List (delete)
a109682 n = a109682_list !! (n-1)
a109682_list = compl a109681_list [0..] where
   compl us'@(u:us) vs'@(v:vs)
       | u == v    = compl us vs
       | u > 3 * v = v : compl us (delete u vs)
       | otherwise = compl us (delete u vs')
-- Reinhard Zumkeller, Nov 19 2013

A109683 Ternary equivalents of A109681.

Original entry on oeis.org

0, 1, 12, 10, 11, 22, 20, 121, 102, 100, 101, 112, 110, 111, 122, 120, 221, 202, 200, 201, 212, 210, 211, 222, 1220, 1021, 1002, 1000, 1001, 1012, 1010, 1011, 1022, 1020, 1121, 1102, 1100, 1101, 1112, 1110, 1111, 1122, 1120, 1221, 1202, 1200
Offset: 0

Views

Author

Philippe Deléham, Aug 08 2005

Keywords

Comments

a(n) = A007089(A109681(n)). - Reinhard Zumkeller, Nov 19 2013

Links

Crossrefs

Cf. A109681, A109682.

Programs

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.

Links

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, ...

Links

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

Links

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

Links

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

Links

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

Links

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).

A325829 "Sloping nonary numbers": write numbers in nonary 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, 7, 17, 9, 10, 11, 12, 13, 14, 15, 16, 26, 18, 19, 20, 21, 22, 23, 24, 25, 35, 27, 28, 29, 30, 31, 32, 33, 34, 44, 36, 37, 38, 39, 40, 41, 42, 43, 53, 45, 46, 47, 48, 49, 50, 51, 52, 62, 54, 55, 56, 57, 58, 59, 60, 61, 71, 63, 64, 65, 66, 67, 68, 69, 70
Offset: 0

Views

Author

Seiichi Manyama, Sep 07 2019

Keywords

Links

Crossrefs

Cf. A102370 (base 2), A109681 (base 3), A325644 (base 4), A325645 (base 5), A325692 (base 6), A325693 (base 7), A325805 (base 8), this sequence (base 9), A103205 (base 10).
Showing 1-9 of 9 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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