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.

A338551 Number of ways to make a checkout score of n in darts.

Original entry on oeis.org

0, 1, 1, 4, 7, 14, 20, 31, 39, 55, 65, 86, 96, 126, 133, 171, 179, 223, 228, 286, 283, 352, 348, 422, 408, 497, 467, 569, 534, 642, 594, 720, 654, 791, 719, 863, 775, 942, 831, 1012, 894, 1082, 945, 1159, 991, 1216, 1037, 1263, 1062, 1311, 1081, 1340, 1110, 1366
Offset: 1

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Author

Carmen Bruni, Nov 02 2020

Keywords

Comments

In other words, the number of ways to achieve a score of n using at most 3 darts and finishing on a double. The maximum checkout score is 170, so this is a finite sequence.

Crossrefs

Programs

  • PARI
    seq()={my(s=x*(1-x^20)/(1-x)+x^25, d=subst(s,x,x^2), g=s+d+subst(s-x^25,x,x^3)); Vecrev((1+g+g^2)*d/x)} \\ Andrew Howroyd, Nov 04 2020
  • Python
    def darts(n):
      if n > 170 or n <= 1:
        return 0
      ans = 0
      singles = list(range(1, 21)) + [25]
      doubles = list(map(lambda x: 2*x, singles))
      triples = list(map(lambda x: 3*x, singles[:-1]))
      throws = singles+doubles+triples
      for i in range(len(throws)):
        for j in range(len(throws)):
          for k in range(len(doubles)):
            dart1 = throws[i]
            dart2 = throws[j]
            dart3 = doubles[k]
            if dart1 + dart2 + dart3 == n:
              ans += 1
        for j in range(len(doubles)):
          dart1 = throws[i]
          dart2 = doubles[j]
          if dart1 + dart2 == n:
            ans += 1
      return ans + (n in doubles)
    for i in range(1,171):
      print(darts(i))
    

A244196 Cumulative angle at the center of successive numbered sectors of a standard competition dartboard, with numbers traversed in order.

Original entry on oeis.org

288, 414, 450, 684, 972, 1080, 1206, 1242, 1296, 1458, 1620, 1674, 1782, 1998, 2196, 2304, 2592, 2826, 2988, 3150
Offset: 1

Views

Author

Philip Mizzi, Jul 21 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. A line collinear with X is then rotated clockwise until each numbered sector is traversed through the center of the sector in question. The total number of degrees is summed as each sector is traversed.

Crossrefs

Showing 1-2 of 2 results.