The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A251781 Numbers whose square is the sum of two distinct positive cubes. 1
 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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 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 LINKS Daniel Arribas, Table of n, a(n) for n = 1..575 EXAMPLE 3^2 = 1^3 + 2^3; 24^2 = 4^3 + 8^3. PROG (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)) (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 CROSSREFS Cf. A024670, A117642, A050801, A217248, A099426 (coprime positive cubes). Sequence in context: A092468 A347108 A027158 * A117642 A220834 A276243 Adjacent sequences: A251778 A251779 A251780 * A251782 A251783 A251784 KEYWORD nonn AUTHOR Daniel Arribas, Dec 08 2014 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 18 18:37 EDT 2024. Contains 372664 sequences. (Running on oeis4.)