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.

A309601 Digits of the 10-adic integer (53/9)^(1/3).

Original entry on oeis.org

3, 7, 3, 8, 6, 7, 0, 5, 3, 0, 8, 5, 3, 4, 8, 1, 3, 0, 9, 0, 3, 2, 9, 2, 3, 6, 3, 2, 4, 3, 5, 1, 5, 2, 9, 8, 0, 7, 6, 0, 3, 9, 9, 4, 2, 5, 3, 0, 3, 2, 0, 3, 2, 8, 2, 8, 7, 8, 3, 1, 0, 0, 4, 6, 4, 1, 8, 9, 4, 8, 5, 3, 5, 3, 7, 3, 1, 6, 7, 9, 1, 1, 8, 5, 0, 2, 5, 7, 6, 3, 8, 9, 4, 2, 7, 3, 0, 3, 6, 6
Offset: 0

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Author

Seiichi Manyama, Aug 09 2019

Keywords

Examples

			       3^3 == 7      (mod 10).
      73^3 == 17     (mod 10^2).
     373^3 == 117    (mod 10^3).
    8373^3 == 1117   (mod 10^4).
   68373^3 == 11117  (mod 10^5).
  768373^3 == 111117 (mod 10^6).
		

Crossrefs

Cf. A309600.

Programs

  • PARI
    N=100; Vecrev(digits(lift(chinese(Mod((53/9+O(2^N))^(1/3), 2^N), Mod((53/9+O(5^N))^(1/3), 5^N)))), N)
    
  • Ruby
    def A309601(n)
      ary = [3]
      a = 3
      n.times{|i|
        b = (a + 3 * (9 * a ** 3 - 53)) % (10 ** (i + 2))
        ary << (b - a) / (10 ** (i + 1))
        a = b
      }
      ary
    end
    p A309601(100)

Formula

Define the sequence {b(n)} by the recurrence b(0) = 0 and b(1) = 3, b(n) = b(n-1) + 3 * (9 * b(n-1)^3 - 53) mod 10^n for n > 1, then a(n) = (b(n+1) - b(n))/10^n.