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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A022566 Numbers that are not the sum of 4 nonnegative cubes. 8
5, 6, 7, 12, 13, 14, 15, 19, 20, 21, 22, 23, 26, 31, 33, 34, 38, 39, 40, 41, 42, 45, 46, 47, 48, 49, 50, 52, 53, 57, 58, 59, 60, 61, 68, 69, 71, 75, 76, 77, 78, 79, 83, 84, 85, 86, 87, 90, 94, 95, 96, 97, 98, 101, 102, 103, 104, 105, 106, 109, 110, 111, 112, 113, 114, 115 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

From Felix Fröhlich, Jun 01 2019: (Start)

Numbers n such that A025448(n) = 0.

Conjecture: The sequence is finite, with 113936676 terms, the largest being 7373170279850 (cf. Deshouillers et al, 2000, Conj. 1 and 2). (End)

LINKS

T. D. Noe, Table of n, a(n) for n=1..10000

Jean-Marc Deshouillers, Francois Hennecart and Bernard Landreau; appendix by I. Gusti Putu Purnaba, 7373170279850, Math. Comp., Vol. 69, No. 229 (2000), 421-439.

Index entries for sequences related to sums of cubes

MATHEMATICA

Complement[Range[134], Take[Union[Total[#^3]&/@Tuples[Range[0, 20], {4}]], 60]] (* Harvey P. Dale, Nov 22 2010 *)

PROG

(PARI) cubes(bound) = my(v=[], x=0); while(1, v=concat(v, [x^3]); x++; if(x^3 > bound, return(v)))

a025448(n) = my(i=0, c=cubes(n)); for(s=1, #c, for(t=s, #c, for(u=t, #c, for(v=u, #c, if(n==c[s]+c[t]+c[u]+c[v], i++))))); i

is(n) = a025448(n)==0 \\ Felix Fröhlich, Jun 01 2019

CROSSREFS

Cf. A025448.

Sequence in context: A154952 A037360 A120521 * A047320 A327301 A247522

Adjacent sequences:  A022563 A022564 A022565 * A022567 A022568 A022569

KEYWORD

nonn,easy,fini,nice

AUTHOR

N. J. A. Sloane

EXTENSIONS

More terms from Larry Reeves (larryr(AT)acm.org), May 16 2001

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 October 15 10:15 EDT 2019. Contains 328026 sequences. (Running on oeis4.)