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 1-4 of 4 results.

A118174 Binary representation of n-th iteration of the Rule 188 elementary cellular automaton starting with a single black cell.

Original entry on oeis.org

1, 0, 1, 1, 0, 0, 1, 0, 1, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 0, 1, 0, 0, 0, 0, 0, 1, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0
Offset: 0

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Author

Eric W. Weisstein, Apr 13 2006

Keywords

Examples

			Triangle starts:
            1;
         0, 1, 1;
      0, 0, 1, 0, 1;
   0, 0, 0, 1, 1, 1, 1;
0, 0, 0, 0, 1, 1, 1, 0, 1;
...
		

Crossrefs

Cf. A118173, decimal representation.
Cf. A265428, total number of ON cells in n-th iteration.
Cf. A265429, total number of ON cells after n iterations.
Cf. A265430, total number of OFF cells in n-th iteration.
Cf. A265431, total number of OFF cells after n iterations.

Programs

  • Mathematica
    lim = 10; a = {}; Do[AppendTo[a, Table[0, k - 1]~Join~Take[#[[k]], k]], {k, Length@ #}] &@ CellularAutomaton[188, {{1}, 0}, lim]; Flatten@ a (* Michael De Vlieger, Dec 09 2015 *)

A265427 Binary representation of the n-th iteration of the "Rule 188" elementary cellular automaton starting with a single ON (black) cell.

Original entry on oeis.org

1, 11, 101, 1111, 11101, 110111, 1011101, 11110111, 111011101, 1101110111, 10111011101, 111101110111, 1110111011101, 11011101110111, 101110111011101, 1111011101110111, 11101110111011101, 110111011101110111, 1011101110111011101, 11110111011101110111
Offset: 0

Views

Author

Robert Price, Dec 08 2015

Keywords

Examples

			From _Michael De Vlieger_, Dec 09 2015: (Start)
First 12 rows:
1
1 1
1 0 1
1 1 1 1
1 1 1 0 1
1 1 0 1 1 1
1 0 1 1 1 0 1
1 1 1 1 0 1 1 1
1 1 1 0 1 1 1 0 1
1 1 0 1 1 1 0 1 1 1
1 0 1 1 1 0 1 1 1 0 1
1 1 1 1 0 1 1 1 0 1 1 1
1 1 1 0 1 1 1 0 1 1 1 0 1
(End)
		

References

  • S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 55.

Crossrefs

Programs

  • Mathematica
    rule = 188; rows = 20; Table[FromDigits[Table[Take[CellularAutomaton[rule,{{1},0}, rows-1, {All,All}][[k]], {rows-k+1, rows+k-1}], {k,1,rows}][[k]]], {k,1,rows}]

Formula

Conjectures from Colin Barker, Dec 09 2015 and Apr 18 2019: (Start)
a(n) = a(n-2) + 10000*a(n-4) - 10000*a(n-6) for n>5.
G.f.: (1+11*x+100*x^2+1100*x^3+1000*x^4-1000*x^5) / ((1-x)*(1+x)*(1-10*x)*(1+10*x)*(1+100*x^2)).
(End)
Conjecture: a(n) = floor(11100*100^n/9999) + 10^n - floor(11100*10^n/9999)*10^n. - Karl V. Keller, Jr., Dec 15 2021

A334244 Decimal representation of n-th iteration of the one-dimensional cellular automaton defined by Rule 950, based on the 4-celled von Neumann neighborhood starting with a single black cell.

Original entry on oeis.org

1, 15, 81, 959, 5185, 61391, 331857, 3929023, 21238849, 251457487, 1359286353, 16093279167, 86994326593, 1029969866703, 5567636901969, 65918071468991, 356328761726017, 4218756574015439, 22805040750465105, 270000420736988095, 1459522608029766721, 17280026927167238095
Offset: 1

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Author

Keywords

Comments

a(n) is the decimal representation of the n-th step based on a simple initial condition, when a(1) = 1.

Crossrefs

Cf. A118171, A118173 (similar examples from elementary cellular automata).

Programs

  • Mathematica
    Table[((1607 +311*(-1)^n)*8^n -1040 +130*(-1)^n -1008*Sqrt[2]*Cos[(2*n-1)*Pi/4] )/8190, {n, 25}] (* G. C. Greubel, May 29 2020 *)
  • PARI
    Vec(x*(1 + 15*x + 17*x^2 - x^3) / ((1 - x)*(1 + x)*(1 - 8*x)*(1 + 8*x)*(1 + x^2)) + O(x^20)) \\ Colin Barker, Jun 10 2020

Formula

a(n) = (-1040 + 130*(-1)^n - (504 + 504*i)*(-i)^n - (504 - 504*i)*i^n + 1607*2^(3*n) + 311*(-1)^n*2^(3*n))/8190 where i = sqrt(-1).
G.f.: (1 + 15*x + 17*x^2 - x^3)/(1 - 64*x^2 - x^4 + 64*x^6).
From G. C. Greubel, May 29 2020: (Start)
a(n) = ( (1607 + 311*(-1)^n)*8^n - (1040 - 130*(-1)^n) - 1008*sqrt(2)*cos((2*n-1)*Pi/4) )/8190.
E.g.f.: (959*cosh(8*x) + 648*sinh(8*x) - 455*cosh(x) - 585*sinh(x) - 504*(cos(x) + sin(x)) )/4095.
(End)
a(n) = 64*a(n-2) + a(n-4) - 64*a(n-6) for n>6. - Colin Barker, Jun 10 2020

A334340 Decimal representation of n-th iteration of the one-dimensional cellular automaton defined by Rule 434, based on the 4-celled von Neumann neighborhood starting with a single black cell.

Original entry on oeis.org

1, 11, 81, 699, 5441, 43723, 349201, 2796731, 22364481, 178965195, 1431573521, 11453377723, 91624653121, 733009857227, 5864040961041, 46912529804475, 375299632087361, 3002400290556619, 24019192622879761, 192153592724761787, 1537228586572923201, 12297829520450964171, 98382633680004977681
Offset: 1

Views

Author

Keywords

Crossrefs

Cf. A118171, A118173 (similar examples from elementary cellular automata).

Formula

a(n) = (1428 + 7*(-4)^n + 2278*(-1)^n + (1800 + 360*i)*(-i)^n + (1800 - 360*i)*i^n - 3*4^n + 85*8^n)/510 where i = sqrt(-1).
G.f.: (-1 - 3*x + 23*x^2 - 3*x^3 + 40*x^4 + 624*x^5 - 1856*x^6)/(-1 + 8*x + 16*x^2 - 128*x^3 + x^4 - 8*x^5 - 16*x^6 + 128*x^7).
Showing 1-4 of 4 results.