A182074 Number of ordered triples (w,x,y) with all terms in {-n,...,0,...,n} and w^2+x*y=n.

12, 16, 24, 56, 40, 48, 56, 64, 148, 80, 72, 96, 120, 96, 104, 304, 120, 128, 168, 144, 184, 176, 120, 208, 524, 160, 184, 256, 232, 192, 264, 224, 264, 304, 184, 760, 344, 176, 280, 400, 328, 256, 344, 352, 392, 416, 200, 384, 1156, 288, 376, 496

Offset

1,1

Comments

For a guide to related sequences, see A211422.

Links

Table of n, a(n) for n=1..52.

Mathematica

t[n_] := t[n] = Flatten[Table[w^2 + x*y - n, {w, -n, n}, {x, -n, n}, {y, -n, n}]]
c[n_] := Count[t[n], 0]
t = Table[c[n], {n, 1, 80}]  (* A182074 *)
t/4                          (* A028387 *)

Crossrefs

Cf. A211422.

Sequence in context: A330546 A189763 A077617 * A192609 A157678 A334560

Adjacent sequences: A182071 A182072 A182073 * A182075 A182076 A182077

Keyword

nonn

Author

Clark Kimberling, Apr 12 2012

Status

approved