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.

A011200 Decimal expansion of 6th root of 5.

Original entry on oeis.org

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

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Author

Keywords

Crossrefs

Cf. A011201 ... A011214 (other roots of 5), A011215 ... A011439 (n-th roots of 6, ..., 20) ; A011440 ... A011519 (n-th root of n = 21, ..., 100).

Programs

A011519 Decimal expansion of 100th root of 100.

Original entry on oeis.org

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

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Author

Keywords

Crossrefs

Cf. A011200 ... A011214 (other roots of 5), A011215 ... A011439 (n-th roots of 6, ..., 20) ; A011440 ... A011519 (n-th root of n = 21, ..., 100).

Programs

A274085 Continued fraction for sixth root of 6.

Original entry on oeis.org

1, 2, 1, 6, 1, 9, 1, 1, 1, 2, 4, 9, 4, 4, 2, 2, 1, 8, 1, 2, 21, 10, 1, 13, 4, 1, 6, 2, 10, 2, 2, 3, 1, 12, 3, 2, 1, 1, 2, 1, 9, 7, 3, 1, 4, 2, 8, 1, 11, 1, 2, 4, 3, 1, 7, 6, 1, 1, 1, 11, 1, 2, 1, 9, 1, 2, 1, 2, 9, 44, 1, 1, 1, 1, 34, 1, 12, 1, 3, 2, 3, 54, 1
Offset: 0

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Examples

			6^(1/6) = 1 + 1/(2 + 1/(1 + 1/(6 + 1/(1 + ...)))).
		

Crossrefs

Cf. A011215 (decimal expansion).

Programs

  • Maple
    numtheory:-cfracpol(x^6-6,100)[2]; # Robert Israel, Jul 31 2016
  • Mathematica
    ContinuedFraction[6^(1/6), {80}] (* Alonso del Arte, Jun 18 2016 *)
  • PARI
    default(realprecision, 210);  contfrac(6^(1/6))

A337840 a(n) is the decimal place of the start of the first occurrence of n in the decimal expansion of n^(1/n).

Original entry on oeis.org

0, 4, 10, 1, 38, 6, 9, 4, 12, 17, 26, 0, 264, 144, 107, 101, 101, 4, 78, 68, 36, 86, 11, 17, 147, 151, 205, 50, 55, 26, 307, 88, 94, 180, 177, 61, 113, 244, 280, 37, 110, 38, 285, 101, 124, 223, 243, 25, 86, 116, 66, 77, 146, 283, 3, 60, 20, 82, 27, 146, 82, 140
Offset: 1

Views

Author

William Phoenix Marcum, Sep 25 2020

Keywords

Comments

Does a(n) exist for all n? Some relatively large values: a(1021) = 67714, a(1111) = 64946. - Chai Wah Wu, Oct 07 2020

Examples

			For n = 1, 1^(1/1) = 1.0000000, so a(1) is 0.
For n = 12, 12^(1/12) ~= 1.2300755, so a(12) = 0.
		

Crossrefs

Cf. A177715.
Decimal expansions of some n^(1/n): A002193, A002581, A005534, A011215, A011231, A011247, A011263, A011279, A011295, A011311, A011327, A011343, A011359.

Programs

  • Mathematica
    max = 3000; a[n_] := SequencePosition[RealDigits[n^(1/n), 10, max][[1]], IntegerDigits[n]][[1, 1]] - 1; Array[a, 100] (* Amiram Eldar, Sep 25 2020 *)
  • PARI
    a(n) = {if (n==1, 0, my(p=10000); default(realprecision, p+1); my(x = floor(10^p*n^(1/n)), d = digits(x), nb = #Str(n)); for(k=1, #d-nb+1, my(v=vector(nb, i, d[k+i-1])); if (fromdigits(v) == n, return(k-1));); error("not found"););} \\ Michel Marcus, Sep 30 2020
    
  • Python
    import gmpy2
    from gmpy2 import mpfr, digits, root
    gmpy2.get_context().precision=10**5
    def A337840(n): # increase precision if -1 is returned
        return digits(root(mpfr(n),n))[0].find(str(n)) # Chai Wah Wu, Oct 07 2020

Extensions

More terms from Amiram Eldar, Sep 25 2020
Showing 1-4 of 4 results.