The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation. Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A217248 Numbers whose square is the sum of two nonnegative cubes. 4
 0, 1, 3, 4, 8, 24, 27, 32, 64, 81, 98, 108, 125, 168, 192, 216, 228, 256, 312, 343, 375, 500, 512, 525, 588, 648, 671, 729, 784, 847, 864, 1000, 1014, 1029, 1183, 1225, 1261, 1323, 1331, 1344, 1372, 1536, 1728, 1824, 2048, 2187, 2197, 2496, 2646, 2744, 2888 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS Numbers N such that N^2 = x^3 + y^3 where x and y are nonnegative integers. First case with 2 solutions is 77976^2 = 228^3 + 1824^3 = 1026^3 + 1710^3, see A051302. - Zak Seidov, Mar 21 2013 LINKS Chai Wah Wu, Table of n, a(n) for n = 1..5000 EXAMPLE 312 is in the sequence because 312^2 = 2^3 + 46^3. MATHEMATICA m = 2888; Sort[Reap[Do[If[IntegerQ[c = Sqrt[a^3 + b^3]], Sow[c]], {a, 0, m^(2/3)}, {b, a, (m^2 - a^3)^(1/3)}]][[2, 1]]] (* Zak Seidov, Mar 21 2013 *) PROG (R)   y=c(); maxsol=3000 #All solutions x)==as.integer(x))y=c(y, x) sort(y) (PARI) is(n)=n*=n; for(k=ceil((n/2-.5)^(1/3)), (n+.5)^(1/3), if(ispower(n-k^3, 3), return(1))); 0 \\ Charles R Greathouse IV, Mar 20 2013 CROSSREFS This sequence with only positive (nonzero) cubes: A050801, and that sequence squared: A050802 A natural extension of the hypotenuse numbers A009003. Sequence in context: A101932 A204521 A073313 * A168382 A155701 A119529 Adjacent sequences:  A217245 A217246 A217247 * A217249 A217250 A217251 KEYWORD nonn AUTHOR Christian N. K. Anderson & Kevin L. Schwartz, Mar 20 2013 EXTENSIONS Offset and a(35) corrected and a(36)-a(51) from Giovanni Resta, Mar 20 2013 STATUS approved

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

Last modified February 27 05:58 EST 2020. Contains 332299 sequences. (Running on oeis4.)