login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A211637 Number of ordered triples (w,x,y) with all terms in {1,...,n} and w^2>x^2+y^2. 4
0, 0, 1, 5, 13, 26, 48, 78, 119, 173, 240, 323, 421, 538, 677, 837, 1020, 1226, 1460, 1723, 2015, 2337, 2694, 3084, 3508, 3969, 4471, 5016, 5601, 6227, 6900, 7619, 8389, 9208, 10078, 11004, 11981, 13015, 14105, 15258, 16472, 17744, 19083, 20487, 21962, 23505 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

For a guide to related sequences, see A211422.

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..1000

MAPLE

b:= proc(n) option remember; 1+floor(sqrt(n)) end:

a:= proc(n) local c, x, y, w;

      c:= 0;

      for x to n do

        for y from x to n do

          w:= b(x^2+y^2);

          if w>n then break fi;

          c:= c+ (n-w+1)*`if`(x=y, 1, 2)

        od

      od: c

    end:

seq (a(n), n=0..50);  # Alois P. Heinz, May 10 2012

MATHEMATICA

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

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

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

Map[t[#] &, Range[0, 50]]   (* A211637 *)

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

CROSSREFS

Cf. A211422.

Sequence in context: A299277 A014813 A180671 * A256111 A322417 A160420

Adjacent sequences:  A211634 A211635 A211636 * A211638 A211639 A211640

KEYWORD

nonn

AUTHOR

Clark Kimberling, Apr 18 2012

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 18 20:42 EDT 2019. Contains 328197 sequences. (Running on oeis4.)