The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A267702 Numbers that are the sum of 3 nonzero squares (A000408) and the sum of 2 positive cubes (A003325). 4
 9, 35, 54, 65, 72, 91, 126, 133, 152, 189, 217, 224, 243, 250, 280, 341, 344, 370, 432, 468, 513, 539, 576, 637, 686, 728, 730, 737, 756, 793, 854, 945, 1001, 1027, 1064, 1072, 1125, 1216, 1241, 1332, 1339, 1358, 1395, 1456, 1458, 1512, 1547, 1674, 1729, 1736, 1755, 1843, 1853 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Intersection of A000408 and A003325. Sequence focuses on the solutions of equation x^3 + y^3 = a^2 + b^2 + c^2 where x, y, a, b, c > 0. LINKS Robert Israel, Table of n, a(n) for n = 1..3649 EXAMPLE 9 is a term because 9 = 1^3 + 2^3 = 1^2 + 2^2 + 2^2. 35 is a term because 35 = 2^3 + 3^3 = 1^2 + 3^2 + 5^2. 54 is a term because 54 = 3^3 + 3^3 = 3^2 + 3^2 + 6^2. MAPLE N:= 1000: # to get all terms <= N S3:= {seq(seq(seq(a^2+b^2+c^2, c = b .. floor(sqrt(N-a^2-b^2))), b=a .. floor(sqrt((N-a^2)/2))), a = 1 .. floor(sqrt(N/3)))}: C2:= {seq(seq(a^3+b^3, b = a .. floor((N-a^3)^(1/3))), a = 1 .. floor((N/2)^(1/3)))}: sort(convert(S3 intersect C2, list)); # Robert Israel, Jan 25 2016 PROG (PARI) isA000408(n) = {my(a, b); a=1; while(a^2+1min(v[1], v[2])>0, thue(T, n))>0; for(n=3, 1e4, if(isA000408(n) && isA003325(n), print1(n, ", "))); CROSSREFS Cf. A000408, A003325. Sequence in context: A265377 A187554 A338010 * A339995 A085366 A304913 Adjacent sequences: A267699 A267700 A267701 * A267703 A267704 A267705 KEYWORD nonn AUTHOR Altug Alkan, Jan 23 2016 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 July 24 22:37 EDT 2024. Contains 374585 sequences. (Running on oeis4.)