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 1-2 of 2 results.

A060109 Numbers in Morse code, with 1 for a dot, 2 for a dash and 0 between digits/letters.

Original entry on oeis.org

22222, 12222, 11222, 11122, 11112, 11111, 21111, 22111, 22211, 22221, 12222022222, 12222012222, 12222011222, 12222011122, 12222011112, 12222011111, 12222021111, 12222022111, 12222022211, 12222022221, 11222022222, 11222012222, 11222011222, 11222011122, 11222011112, 11222011111
Offset: 0

Views

Author

Henry Bottomley, Feb 28 2001

Keywords

Examples

			a(10) = 12222022222 since 1 is ".----" and 0 is "-----".
		

Crossrefs

Cf. A059852 (Morse code for letters), A008777 (number of dots and dashes).
Cf. A060110 (these base-3 numbers converted to decimal), A321332 (duration of the code for n).

Programs

  • Haskell
    import Data.List (inits, tails)
    a060109 n = if n == 0 then 22222 else read (conv n) :: Integer where
       conv 0 = []
       conv x = conv x' ++ mCode !! d where (x', d) = divMod x 10
       mCode = map ('0' :) (mc ++ (reverse $ init $ tail $ map reverse mc))
       mc = zipWith (++) (inits "111111") (tails "22222")
    -- Reinhard Zumkeller, Feb 20 2015
    
  • Mathematica
    With[{a = Association@ Array[# -> If[# < 6, PadRight[ConstantArray[1, #], 5, 2], PadRight[ConstantArray[2, # - 5], 5, 1]] &, 10, 0]}, Array[FromDigits@ Flatten@ Riffle[Map[Lookup[a, #] &, IntegerDigits[#]], 0] &, 25]] (* Michael De Vlieger, Nov 02 2020 *)
  • PARI
    apply( {A060109(n)=if(n>9,self()(n\10)*10^6)+fromdigits([1+(abs(k-n%10)>2)|k<-[3..7]])}, [0..39]) \\ M. F. Hasler, Jun 22 2020

Formula

a(n) A007089(A060110(n)) = a(floor(n/10))*10^6 + a(n%10) for n > 9 and a(n) = 33333 - a(n-5) for n%10 > 4, where % is the modulo (remainder) operator. - M. F. Hasler, Jun 22 2020

A326345 a(n) is the number of arm movements when expressing n in flag semaphore, counting the movement of each arm separately.

Original entry on oeis.org

6, 6, 6, 6, 5, 5, 6, 6, 6, 5, 7, 6, 7
Offset: 0

Views

Author

Felix Fröhlich, Sep 11 2019

Keywords

Comments

Each number is followed by the "rest"/"space" position, crossing both arms in front of the body, adding two further movements to each flag sequence.

Examples

			n    Flag sequence
0     __                   __
     |  |     /\          |  |
     |__|    / /          |__|
        |   /\/           |
        |  /              |
                       /
                      /
                     /\
                    / /
                    \/
1     __
     |  |     /\
     |__|    / /
        |   /\/
        |  /
                       /    |
                      /     |
                     /\   __|
                    / /  |  |
                    \/   |__|
2     __
     |  |     /\
     |__|    / /
        |   /\/
        |  /      ----------
                  |____|      |
                              |
                            __|
                           |  |
                           |__|
3
      __
     |  |     /\    /\
     |__|    / /    \ \
        |   /\/      \/\
        |  /            \
                             |
                             |
                           __|
                          |  |
                          |__|
4     __             __
     |  |     /\    |  |
     |__|    / /    |__|
        |   /\/        |
        |  /           |
                            |
                            |
                          __|
                         |  |
                         |__|
5     __
     |  |     /\         /\
     |__|    / /        / /
        |   /\/        /\/
        |  /          /
                   |
                   |
                   |__
                   |  |
                   |__|
6     __
     |  |     /\
     |__|    / /
        |   /\/
        |  /         ----------
                   |     |____|
                   |
                   |__
                   |  |
                   |__|
7     __
     |  |     /\
     |__|    / /
        |   /\/
        |  /
                   |    \
                   |     \
                   |__   /\
                   |  |  \ \
                   |__|   \/
8     __
     |  |     /\
     |__|    / /
        |   /\/
        |  /       ----------
                   |____|      /
                              /
                             /\
                            / /
                            \/
9     __             __
     |  |     /\    |  |
     |__|    / /    |__|
        |   /\/        |
        |  /           |
                          /
                         /
                        /\
                       / /
                       \/
10    __                                 __
     |  |     /\                        |  |
     |__|    / /                        |__|
        |   /\/                         |
        |  /                            |
                       /    |        /
                      /     |       /
                     /\   __|      /\
                    / /  |  |     / /
                    \/   |__|     \/
11    __
     |  |     /\
     |__|    / /
        |   /\/
        |  /
                       /    |        /    |
                      /     |       /     |
                     /\   __|      /\   __|
                    / /  |  |     / /  |  |
                    \/   |__|     \/   |__|
12    __
     |  |     /\
     |__|    / /
        |   /\/
        |  /                     ----------
                       /    |    |____|      |
                      /     |                |
                     /\   __|              __|
                    / /  |  |             |  |
                    \/   |__|             |__|
		

Crossrefs

Cf. A321332.
Showing 1-2 of 2 results.