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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.

User: Daniel Arribas

Daniel Arribas's wiki page.

Daniel Arribas has authored 1 sequences.

A251781 Numbers whose square is the sum of two distinct positive cubes.

Original entry on oeis.org

3, 24, 81, 98, 168, 192, 228, 312, 375, 525, 588, 648, 671, 784, 847, 1014, 1029, 1183, 1225, 1261, 1323, 1344, 1536, 1824, 2187, 2496, 2646, 2888, 3000, 3993, 4200, 4225, 4536, 4563, 4644, 4704, 5184, 5368, 6156, 6272, 6292, 6371, 6591, 6696, 6776, 6877, 8112
Offset: 1

Author

Daniel Arribas, Dec 08 2014

Keywords

Comments

This list contains A117642 (if n=3*k^3, then n^2 = 9*k^6 = 8*k^6 + k^6 = (2*k^2)^3 + (k^2)^3). (Old comment rewritten as suggested by Michel Marcus, Dec 10 2014.)
Subsequence of A050801 and A217248. - Wolfdieter Lang, Jan 04 2015

Examples

			3^2 = 1^3 + 2^3; 24^2 = 4^3 + 8^3.
		

Crossrefs

Cf. A024670, A117642, A050801, A217248, A099426 (coprime positive cubes).

Programs

  • Python
    def aupto(limit):
      c = [i**3 for i in range(1, int(limit**(2/3))+2) if i**3 <= limit**2]
      cc = [c1 + c2 for i, c1 in enumerate(c) for c2 in c[i+1:]]
      return sorted([i for i in range(1, limit+1) if i*i in cc])
    print(aupto(8122)) # Michael S. Branicky, Mar 24 2021
  • Sage
    L = []
    for k in range(1,10^3):
        for l in range(k + 1,10^3):
            if is_square(k**3+l**3):
                L.append(sqrt(k**3+l**3))