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!)
 A273843 Numbers that are the average of 3 nonzero squares and the average of 2 positive cubes. 0
 1, 8, 14, 27, 36, 63, 64, 76, 112, 140, 172, 185, 216, 234, 260, 288, 343, 364, 378, 427, 504, 512, 536, 608, 666, 679, 728, 729, 868, 896, 972, 1000, 1030, 1099, 1112, 1120, 1161, 1270, 1331, 1376, 1404, 1463, 1480, 1628, 1688, 1728, 1750, 1764, 1859, 2052, 2080, 2156 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Values of (x^3 + y^3)/2 such that (x^3 + y^3)/2 = (a^2 + b^2 + c^2)/3 where x, y, a, b, c > 0, is soluble. LINKS EXAMPLE 14 is a term because 14 = (1^3 + 3^3)/2 = (1^2 + 4^2 + 5^2)/3. MATHEMATICA repQ[n_, k_, e_] := {} != Quiet@ IntegerPartitions[n, {k}, Range[n^ (1/e) ]^e, 1]; Select[Range@ 2156, repQ[2*#, 2, 3] && repQ[3*#, 3, 2] &] (* Giovanni Resta, Jun 03 2016 *) PROG (PARI) isA000408(n) = my(a, b) ; a=1 ; while(a^2+1

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 May 9 13:42 EDT 2021. Contains 343742 sequences. (Running on oeis4.)