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.

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A269020 a(n) = ceiling(n^(1+1/n)).

Original entry on oeis.org

1, 3, 5, 6, 7, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70
Offset: 1

Views

Author

Bob Selcoe, Feb 17 2016

Keywords

Examples

			a(5)=7 because 5^(6/5) ~ 6.8986; a(6)=9 because 6^(7/6) ~ 8.088.
		

Crossrefs

Cf. A059921 (floor(n^(1+1/n))), A269023 (complementary sequence).

Programs

  • Magma
    [Ceiling(n^(1+1/n)): n in [1..70]]; // Vincenzo Librandi, Feb 18 2016
    
  • Mathematica
    Table[Ceiling[n^(1 + 1 / n)], {n, 100}] (* Vincenzo Librandi, Feb 18 2016 *)
  • Python
    from sympy import integer_nthroot
    def A269020(n):
        a, b = integer_nthroot(n**(n+1),n)
        return a+(b^1) # Chai Wah Wu, Sep 04 2024

Formula

a(n) = A059921(n) + 1, n>=2.

A269024 a(n) = A269020(n) - n.

Original entry on oeis.org

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

Views

Author

Bob Selcoe, Feb 18 2016

Keywords

Comments

Same as subtracting the index (n) from the output (a(n)) in A269020.

Examples

			a(20)=4 because A269020(20) = 24, and 24-20=4.
a(5)=2, a(6)=3 and A269023(3)=8, so a(6) = 8-6+1 = 3.
		

Crossrefs

Formula

a(n) = either a(n-1) or a(n-1)+1.
When a(n) = a(n-1)+1, a(n) = A269023(a(n)) - n + 1.
Showing 1-2 of 2 results.