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 1-10 of 11 results. Next

A069892 Sequence around outside of single zero roulette wheel.

Original entry on oeis.org

0, 32, 15, 19, 4, 21, 2, 25, 17, 34, 6, 27, 13, 36, 11, 30, 8, 23, 10, 5, 24, 16, 33, 1, 20, 14, 31, 9, 22, 18, 29, 7, 28, 12, 35, 3, 26, 0, 32, 15, 19, 4, 21, 2, 25, 17, 34, 6, 27, 13, 36, 11, 30, 8, 23, 10, 5, 24, 16, 33, 1, 20, 14, 31, 9, 22, 18, 29, 7, 28, 12, 35, 3, 26
Offset: 1

Views

Author

Brett Stevens (brett(AT)math.carleton.ca), Apr 09 2002

Keywords

Comments

The roulette wheel and the dartboard are good candidates for what might be considered an "Anti-Gray Code", a sequence of objects from a combinatorial family such that nearby elements are far apart in some metric.

Links

Crossrefs

Cf. A003833, A008575, A069893, A291151.

A069893 Sequence around outside of double zero roulette wheel.

Original entry on oeis.org

0, 27, 10, 25, 29, 12, 8, 19, 31, 18, 6, 21, 33, 16, 4, 23, 35, 14, 2, 0, 28, 9, 26, 30, 11, 7, 20, 32, 17, 5, 22, 34, 15, 3, 24, 36, 13, 1, 0, 27, 10, 25, 29, 12, 8, 19, 31, 18, 6, 21, 33, 16, 4, 23, 35, 14, 2, 0, 28, 9, 26, 30, 11, 7, 20, 32, 17, 5, 22, 34, 15, 3, 24, 36, 13, 1
Offset: 1

Views

Author

Brett Stevens (brett(AT)math.carleton.ca), Apr 09 2002

Keywords

Comments

Double zeros, "00", occur before 27s in the sequence but have been replaced here by 0's.
The roulette wheel and the dartboard are good candidates for what might be considered an "Anti-Gray Code", a sequence of objects from a combinatorial family such that nearby elements are far apart in some metric.

References

  • G. Simmons, An Application of Maximum-Minimum Distance Circuits on Hypercubes, Lecture Notes in Mathematics, Vol. 686 (1977) pp. 290-299.

Links

Crossrefs

Cf. A069892, A008575, A003833.

A008575 Sectors on dartboard.

Original entry on oeis.org

1, 18, 4, 13, 6, 10, 15, 2, 17, 3, 19, 7, 16, 8, 11, 14, 9, 12, 5, 20, 25, 50
Offset: 1

Views

Author

aubrey.moore(AT)saipan.com; C. R. Sloane

Keywords

Links

Crossrefs

Cf. A003833.

A104158 Numbers on a standard, London, or clock dartboard read in a counterclockwise direction.

Original entry on oeis.org

20, 5, 12, 9, 14, 11, 8, 16, 7, 19, 3, 17, 2, 15, 10, 6, 13, 4, 18, 1, 20, 5, 12, 9, 14, 11, 8, 16, 7, 19, 3, 17, 2, 15, 10, 6, 13, 4, 18, 1, 20, 5, 12, 9, 14, 11, 8, 16, 7, 19, 3, 17, 2, 15, 10, 6, 13, 4, 18, 1, 20, 5, 12, 9, 14, 11, 8, 16, 7, 19, 3, 17, 2, 15, 10, 6
Offset: 0

Views

Author

Andrew G. West (WestA(AT)wlu.edu), Mar 09 2005

Keywords

Comments

Sequence is periodic with period 20. - Michel Marcus, Jul 26 2013

References

  • GCHQ, The GCHQ Puzzle Book, Penguin, 2016. See page 82.

Links

Crossrefs

Cf. A003833, A008575.

Programs

  • Mathematica
    PadRight[{}, 100, {20, 5, 12, 9, 14, 11, 8, 16, 7, 19, 3, 17, 2, 15, 10, 6, 13, 4, 18, 1}] (* Paolo Xausa, Jul 17 2025 *)

A104159 Numbers on a Manchester or Log-End dartboard, as read in a standard, clockwise direction.

Original entry on oeis.org

4, 20, 1, 16, 6, 17, 8, 12, 9, 14, 5, 19, 2, 15, 3, 18, 7, 11, 10, 13, 4, 20, 1, 16, 6, 17, 8, 12, 9, 14, 5, 19, 2, 15, 3, 18, 7, 11, 10, 13, 4, 20, 1, 16, 6, 17, 8, 12, 9, 14, 5, 19, 2, 15, 3, 18, 7, 11, 10, 13, 4, 20, 1, 16, 6, 17, 8, 12, 9, 14, 5, 19, 2, 15, 3
Offset: 1

Views

Author

Andrew G. West (WestA(AT)wlu.edu), Mar 09 2005

Keywords

Comments

Sequence is periodic with period 20. - Michel Marcus, Jul 26 2013

Links

Crossrefs

Cf. A003833, A104158.

Programs

  • Mathematica
    PadRight[{}, 100, {4, 20, 1, 16, 6, 17, 8, 12, 9, 14, 5, 19, 2, 15, 3, 18, 7, 11, 10, 13}] (* Paolo Xausa, Jul 14 2025 *)

A076119 Every second sector of a dartboard, starting at the top (20) and working around clockwise.

Original entry on oeis.org

20, 18, 13, 10, 2, 3, 7, 8, 14, 12, 20, 18, 13, 10, 2, 3, 7, 8, 14, 12, 20, 18, 13, 10, 2, 3, 7, 8, 14, 12, 20, 18, 13, 10, 2, 3, 7, 8, 14, 12, 20, 18, 13, 10, 2, 3, 7, 8, 14, 12, 20, 18, 13, 10, 2, 3, 7, 8, 14, 12, 20, 18, 13, 10, 2, 3, 7, 8, 14, 12, 20, 18, 13, 10, 2
Offset: 1

Views

Author

Darren Izzard (zysyshelp(AT)yahoo.com), Oct 31 2002

Keywords

Comments

Period 10: repeat [20,18,13,10,2,3,7,8,14,12]. - Wesley Ivan Hurt, Jul 15 2015

Links

Crossrefs

Cf. A003833.

Programs

  • Magma
    R:=[20,18,13,10,2,3,7,8,14,12]; [n le 10 select R[n] else Self(n-10): n in [1..100]]; // Wesley Ivan Hurt, Jul 15 2015
  • Magma
    &cat [[20, 18, 13, 10, 2, 3, 7, 8, 14, 12]: n in [1..7]]; // Vincenzo Librandi, Jul 16 2015
  • Maple
    A076119:=n->[20,18,13,10,2,3,7,8,14,12][(n mod 10)+1]: seq(A076119(n), n=0..100); # Wesley Ivan Hurt, Jul 15 2015
  • Mathematica
    CoefficientList[Series[(20 + 18 x + 13 x^2 + 10 x^3 + 2 x^4 + 3 x^5 + 7 x^6 + 8 x^7 + 14 x^8 + 12 x^9)/(1 - x^10), {x, 0, 100}], x] (* Wesley Ivan Hurt, Jul 15 2015 *)
  • PARI
    a(n)=[12,20,18,13,10,2,3,7,8,14][n%10+1] \\ Charles R Greathouse IV, Aug 20 2015

Formula

G.f.: x*(20+18*x+13*x^2+10*x^3+2*x^4+3*x^5+7*x^6+8*x^7+14*x^8+12*x^9) / (1-x^10). a(n) = a(n-10), n>10. - Wesley Ivan Hurt, Jul 15 2015

A244512 The angle of the center of each numbered sector of a standard competition dartboard.

Original entry on oeis.org

288, 54, 90, 324, 252, 0, 126, 162, 216, 18, 180, 234, 342, 198, 36, 144, 72, 306, 108, 270
Offset: 1

Views

Author

Philip Mizzi, Jun 29 2014

Keywords

Comments

A standard dartboard is divided into 20 sectors each subtending an angle of 18 degrees.
The sequence is generated by considering the positive x-axis to be running through the center of the sector numbered "6" and defining this to be 0 degrees. The angular position of each sector is then defined relative to this position through a clockwise rotation of a line collinear with x until the line divides the sector of interest. The numbers are then sectors are ordered from 1 to 20 generating the full sequence.
It is a mere formality to fully define the bounds of each sector by adding and subtracting 9 degrees from each of the numbers in the sequence.

Links

Crossrefs

Cf. A003833, A008575.

Formula

n = A003833(a(n)/18+6). - Jens Kruse Andersen, Jul 19 2014

Extensions

Incorrect term removed by Jens Kruse Andersen, Jul 19 2014

A117883 Alternate numbers on a dartboard, read clockwise.

Original entry on oeis.org

1, 4, 6, 15, 17, 19, 16, 11, 9, 5
Offset: 1

Views

Author

Danny Williamson (daniel.williamson(AT)durham.ac.uk), May 02 2006

Keywords

Comments

These usually appear as beds with white backgrounds with green doubles beds.

Crossrefs

Cf. A003833, A008575, A104158, A104159.

A385491 Period 8: repeat [1, 8, 4, 3, 6, 5, 7, 2].

Original entry on oeis.org

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

Views

Author

Christopher W Moriarty, Jun 30 2025

Keywords

Comments

The Chevrolet V8 engine cylinder firing order used in nearly all GMC small block (265-400 cubic inch) and big block (396-454 cubic inch) engines dating back to the 1950's.

References

  • John Baechtel, Chevy Small-Block V-8 Interchange Manual: 2nd Edition. CarTech Inc., 2010. ISBN: 1934709405.
  • Bill Jenkins, The Chevrolet Racing Engine. HP Books, 1976.

Links

Crossrefs

Cf. A003833, A069892, A385634.

Programs

  • Mathematica
    PadRight[{}, 100, {1, 8, 4, 3, 6, 5, 7, 2}] (* Paolo Xausa, Jul 12 2025 *)

Formula

G.f.: -(2*x^6+5*x^5+6*x^3-3*x^2+7*x+1)/((x-1)*(x^2+1)*(x^4+1)). - Alois P. Heinz, Jun 30 2025

A233820 Period 4: repeat [20, 5, 15, 10].

Original entry on oeis.org

20, 5, 15, 10, 20, 5, 15, 10, 20, 5, 15, 10, 20, 5, 15, 10, 20, 5, 15, 10, 20, 5, 15, 10, 20, 5, 15, 10, 20, 5, 15, 10, 20, 5, 15, 10, 20, 5, 15, 10, 20, 5, 15, 10, 20, 5, 15, 10, 20, 5, 15, 10, 20, 5, 15, 10, 20, 5, 15, 10, 20, 5, 15, 10, 20, 5, 15, 10, 20, 5
Offset: 1

Views

Author

Arkadiusz Wesolowski, Dec 16 2013

Keywords

Comments

Clockwise sectors around outside of London Fives dartboard.

Links

Crossrefs

Cf. A003833.

Programs

  • Magma
    &cat[[20,5,15,10]: n in [1..17]]; // Bruno Berselli, Dec 16 2013
  • Maple
    seq(op([20, 5, 15, 10]), n=0..50); # Wesley Ivan Hurt, Jul 07 2016
  • Mathematica
    Flatten[Table[{20, 5, 15, 10}, {17}]]
  • PARI
    a(n)=[10,20,5,15][n%4+1] \\ Charles R Greathouse IV, Aug 20 2015

Formula

From Bruno Berselli, Dec 16 2013: (Start)
G.f.: 5*x*(4 + x + 3*x^2 + 2*x^3)/((1 - x)*(1 + x)*(1 + x^2)).
a(n) = 5*(I^(n*(n-1)) - 2*(-1)^n + 5)/2. (End)
From Wesley Ivan Hurt, Jul 07 2016: (Start)
a(n) = 5*(5 + cos(n*Pi/2) - 2*cos(n*Pi) + sin(n*Pi/2) - 2*I*sin(n*Pi))/2.
a(n) = a(n-4) for n>4. (End)
Showing 1-10 of 11 results. Next

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

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