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A211437 Number of ordered triples (w,x,y) with all terms in {-n,...,0,...,n} and w*x*y=n. 2
1, 4, 12, 12, 24, 12, 36, 12, 40, 24, 36, 12, 72, 12, 36, 36, 60, 12, 72, 12, 72, 36, 36, 12, 120, 24, 36, 40, 72, 12, 108, 12, 84, 36, 36, 36, 144, 12, 36, 36, 120, 12, 108, 12, 72, 72, 36, 12, 180, 24, 72, 36, 72, 12, 120, 36, 120, 36, 36, 12, 216, 12, 36, 72 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

For a guide to related sequences, see A211422.

LINKS

Table of n, a(n) for n=0..63.

MATHEMATICA

t[n_] := t[n] = Flatten[Table[w*x*y - n, {w, -n, n}, {x, -n, n}, {y, -n, n}]]

c[n_] := Count[t[n], 0]

t = Table[c[n], {n, 0, 80}]  (* A211437 *)

t/4                  (* A007425 for n>0 *)

CROSSREFS

Cf. A211422, A007425.

Sequence in context: A120213 A005886 A096442 * A195199 A294628 A323188

Adjacent sequences:  A211434 A211435 A211436 * A211438 A211439 A211440

KEYWORD

nonn

AUTHOR

Clark Kimberling, Apr 12 2012

STATUS

approved

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Last modified February 23 07:31 EST 2020. Contains 332159 sequences. (Running on oeis4.)