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A213499 Number of (w,x,y) with all terms in {0,...,n} and w != min(|w-x|,|x-y|) 3
0, 4, 17, 47, 96, 176, 286, 439, 634, 885, 1188, 1561, 1997, 2515, 3108, 3796, 4569, 5451, 6429, 7528, 8735, 10076, 11535, 13142, 14878, 16774, 18811, 21021, 23382, 25930, 28640, 31549, 34632, 37927, 41406, 45111, 49011, 53149, 57494 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

a(n)+A213497(n) = (n+1)^3.

For a guide to related sequences, see A212959.

LINKS

Table of n, a(n) for n=0..38.

Index entries for linear recurrences with constant coefficients, signature (1,2,-1,-2,-1,2,1,-1).

FORMULA

a(n) = a(n-1)+2*a(n-2)-a(n-3)-2*a(n-4)-a(n-5)+2*a(n-6)+a(n-7)-a(n-8).

G.f.:  (x*(4 + 13*x + 22*x^2 + 19*x^3 + 11*x^4 + 3*x^5))/((-1 + x)^4 (1 + x)^2 (1 + x + x^2)).

MATHEMATICA

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

(Do[If[w != Min[Abs[w - x], Abs[x - y]], s = s + 1],

{w, 0, n}, {x, 0, n}, {y, 0, n}]; s)]];

m = Map[t[#] &, Range[0, 60]]   (* A213499 *)

CROSSREFS

Cf. A212959.

Sequence in context: A212577 A332863 A119949 * A213502 A273334 A273766

Adjacent sequences:  A213496 A213497 A213498 * A213500 A213501 A213502

KEYWORD

nonn,easy

AUTHOR

Clark Kimberling, Jun 14 2012

STATUS

approved

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Last modified May 7 19:23 EDT 2021. Contains 343652 sequences. (Running on oeis4.)