login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A297931 Numbers that are not the sum of a square and 3 nonnegative cubes. 0
15, 22, 23, 48, 86, 94, 112, 120, 139, 184, 203, 211, 230, 237, 263, 301, 309, 312, 335, 373, 399, 1014, 1056, 1455, 1644, 2029, 2272, 2658, 3309, 3469, 4019, 6502, 11101 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

After 11101, there are no more terms up to 570000.

No more terms < 10^10; is this sequence finite? - Mauro Fiorentini, Jan 26 2019

LINKS

Table of n, a(n) for n=1..33.

Eric Weisstein's World of Mathematics, Waring's Problem

MATHEMATICA

t1={};

Do[Do[If[x^2+y^2+z^2+w^3==n, AppendTo[t1, n]&&Break[]], {x, 0, n^(1/2)}, {y, x, (n-x^2)^(1/2)}, {z, y, (n-x^2-y^2)^(1/2)}, {w, 0, (n-x^2-y^2-z^2)^(1/3)}], {n, 0, 5.7*10^5}];

t2={};

Do[If[FreeQ[t1, k]==True, AppendTo[t2, k]], {k, 0, 5.7*10^5}];

t2

CROSSREFS

Cf. A004215, A022552, A022557, A022561, A022566, A111151.

Sequence in context: A236764 A300958 A066758 * A018888 A115174 A092783

Adjacent sequences:  A297928 A297929 A297930 * A297932 A297933 A297934

KEYWORD

nonn

AUTHOR

XU Pingya, Jan 08 2018

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 17 20:45 EDT 2019. Contains 325109 sequences. (Running on oeis4.)