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.

A217175 a(n) is the first digit (from the left) to appear n times in succession in the decimal representation of the Fibonacci(A217165(n)).

Original entry on oeis.org

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

Views

Author

V. Raman, Sep 27 2012

Keywords

Crossrefs

Programs

  • Mathematica
    k = 0; Join[{0}, Table[While[d = IntegerDigits[Fibonacci[k]]; prt = Partition[Differences[d], n - 1, 1]; ! MemberQ[prt, Table[0, {n - 1}]], k++]; d[[Position[prt, Table[0, {n - 1}]][[1, 1]]]], {n, 2, 8}]] (* T. D. Noe, Oct 03 2012 *)
  • Python
    def A217175(n):
        if n == 1:
            return 0
        else:
            l, y, x = [str(d)*n for d in range(10)], 0, 1
            for m in range(1, 10**9):
                s = str(x)
                for k in range(10):
                    if l[k] in s:
                        return k
                y, x = x, y+x
            return 'search limit reached'
    # Chai Wah Wu, Dec 17 2014

Extensions

a(10)-a(11) from Chai Wah Wu, Dec 17 2014
a(12)-a(15) from Nick Hobson, Feb 14 2024

A217191 a(n) is the number of digits in the decimal representation of the smallest Fibonacci number that contains n consecutive identical digits.

Original entry on oeis.org

1, 2, 10, 14, 25, 185, 460, 1357, 13027, 28264, 73895, 242950, 1077514, 1521516, 7806974
Offset: 1

Views

Author

V. Raman, Sep 27 2012

Keywords

Comments

Number of digits in Fibonacci(k) is equal to floor(1 + k*log_10((1+sqrt(5))/2)-log_10(sqrt(5))).

Crossrefs

Programs

  • Mathematica
    k = 0; Join[{1}, Table[While[d = IntegerDigits[Fibonacci[k]]; ! MemberQ[Partition[Differences[d], n - 1, 1], Table[0, {n - 1}]], k++]; Length[d], {n, 2, 8}]] (* T. D. Noe, Oct 02 2012 *)
  • Python
    def A217191(n):
        if n == 1:
            return 1
        else:
            l, y, x = [str(d)*n for d in range(10)], 0, 1
            for m in range(1, 10**9):
                s = str(x)
                for k in l:
                    if k in s:
                        return len(s)
                y, x = x, y+x
            return 'search limit reached'
    # Chai Wah Wu, Dec 17 2014

Extensions

a(10)-a(11) from Chai Wah Wu, Dec 17 2014
a(12)-a(15) from Nick Hobson, Feb 15 2024
Showing 1-2 of 2 results.