This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A267414 Integers n such that n! = x^3 + y^3 + z^3 where x, y and z are nonnegative integers, is soluble. 0
 0, 1, 2, 4, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 20, 21 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS EXAMPLE 0 is a term because 0! = 1 = 0^3 + 0^3 + 1^3. 2 is a term because 2! = 2 = 0^3 + 1^3 + 1^3. 4 is a term because 4! = 24 = 2^3 + 2^3 + 2^3. From Chai Wah Wu, Jan 18 2016 : (Start) 9! = 36^3 + 52^3 + 56^3 10! = 4^3 + 96^3 + 140^3 11! = 105^3 + 222^3 + 303^3 12! = 35^3 + 309^3 + 766^3 14! = 135^3 + 3153^3 + 3822^3 15! = 1092^3 + 2040^3 + 10908^3 16! = 7644^3 + 21192^3 + 22212^3 17! = 9984^3 + 22848^3 + 69984^3 18! = 18900^3 + 54060^3 + 184080^3 19! = 131040^3 + 331200^3 + 436320^3 20! = 87490^3 + 1034430^3 + 1098440^3 21! = 59850^3 + 2072070^3 + 3481380^3 (End) MAPLE isA267414 := proc(n)     local nf, x, y ;     nf := n! ;     for x from 0 do         if 3*x^3 > nf then             return false;         end if;         for y from x do             if x^3+2*y^3 > nf then                 break;             end if;             if isA000578(nf-x^3-y^3) then                 return true;             end if;         end do:     end do: end proc: for n from 0 to 1000 do     if isA267414(n) then         print(n) ;     end if; end do: # R. J. Mathar, Jan 23 2016 CROSSREFS Cf. A000142, A000578, A003072, A003325. Sequence in context: A258710 A246515 A275658 * A072583 A178488 A226821 Adjacent sequences:  A267411 A267412 A267413 * A267415 A267416 A267417 KEYWORD nonn,more AUTHOR Altug Alkan, Jan 14 2016 EXTENSIONS a(12)-a(16) from Chai Wah Wu, Jan 18 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 | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified October 22 21:09 EDT 2018. Contains 316505 sequences. (Running on oeis4.)