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.

A373868 Integers that are not perfect fifth powers.

Original entry on oeis.org

2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70
Offset: 1

Views

Author

Chai Wah Wu, Jun 19 2024

Keywords

Comments

Complement of A000584.

Crossrefs

Programs

  • Mathematica
    Complement[Range[#^5], Range[#]^5] & [3] (* Paolo Xausa, Jul 03 2024 *)
  • Python
    from sympy import integer_nthroot
    def A373868(n): return n+(k:=integer_nthroot(n, 5)[0])+(n>=(k+1)**5-k)

A305553 Numbers that are not the sum of 2 squares and a 4th power.

Original entry on oeis.org

7, 12, 15, 22, 23, 28, 31, 39, 43, 44, 47, 55, 60, 63, 67, 70, 71, 76, 78, 79, 87, 92, 93, 95, 103, 108, 111, 112, 119, 124, 127, 135, 140, 143, 151, 156, 159, 167, 168, 172, 175, 177, 183, 184, 188, 191, 192, 199, 204, 207, 214, 215, 220, 223, 231, 236
Offset: 1

Views

Author

XU Pingya, Jun 20 2018

Keywords

Comments

Numbers of the form 4*A017101(k) are terms of this sequence.
m is a term iff 16m is also.

Crossrefs

Subsequence of A000037, A140823 and A022544.
A004215 and A214891 are subsequences.

Programs

  • Mathematica
    n=239;
    t=Union@Flatten@Table[x^2+y^2+z^4, {x,0,n^(1/2)}, {y,x,(n-x^2)^(1/2)}, {z,0,(n-x^2-y^2)^(1/4)}];
    Complement[Range[0,n], t]
Showing 1-2 of 2 results.