A212093 - OEIS

A212093

Number of (w,x,y,z) with all terms in {1,...,n} and w^2<=x^2+y^2+z^2.

0, 1, 15, 76, 234, 565, 1161, 2145, 3644, 5825, 8854, 12940, 18300, 25173, 33814, 44524, 57587, 73346, 92127, 114312, 140272, 170421, 205198, 245043, 290413, 341832, 399774, 464801, 537425, 618289, 707923, 807009, 916110, 1035937

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OFFSET

0,3

COMMENTS

a(n)+A212094(n)=n^4. For a guide to related sequences, see A211795.

LINKS

Table of n, a(n) for n=0..33.

MATHEMATICA

t = Compile[{{n, _Integer}}, Module[{s = 0},

(Do[If[w^2 <= x^2 + y^2 + z^2, s = s + 1],

{w, 1, #}, {x, 1, #}, {y, 1, #}, {z, 1, #}] &[n]; s)]];

Map[t[#] &, Range[0, 50]] (* A212093 *)

(* Peter J. C. Moses, Apr 13 2012 *)

CROSSREFS

Cf. A211795.

Sequence in context: A049391 A370739 A247264 * A212241 A000477 A302376

Adjacent sequences: A212090 A212091 A212092 * A212094 A212095 A212096

KEYWORD

nonn

AUTHOR

Clark Kimberling, May 02 2012

STATUS

approved