A212243 Number of (w,x,y,z) with all terms in {1,...,n} and 2wx+yz=n.

0, 0, 0, 1, 2, 4, 7, 8, 14, 13, 24, 19, 33, 26, 48, 32, 60, 41, 75, 49, 92, 58, 109, 66, 127, 76, 146, 88, 168, 96, 184, 106, 212, 122, 227, 126, 263, 140, 271, 158, 304, 163, 326, 175, 363, 196, 366, 198, 425, 212, 416, 240, 474, 238, 488, 250, 528, 284

Offset: 0

Author

Clark Kimberling, May 08 2012

Keywords

• nonn

Comments

For a guide to related sequences, see A211795.

Crossrefs

Cf. A211795.

Programs

Mathematica

t = Compile[{{n, _Integer}}, Module[{s = 0},
(Do[If[2 w*x + y*z == n, s = s + 1],
{w, 1, #}, {x, 1, #}, {y, 1, #}, {z, 1, #}] &[n]; s)]];
Map[t[#] &, Range[0, 60]]  (* A212243 *)
(* Peter J. C. Moses, Apr 13 2012 *)