login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A212062 Number of (w,x,y,z) with all terms in {1,...,n} and w^2 = x*y*z. 2

%I #14 Nov 27 2016 06:59:55

%S 0,1,4,7,16,19,31,34,50,68,80,83,122,125,137,149,185,188,233,236,269,

%T 281,293,296,368,410,422,456,489,492,570,573,630,642,654,666,792,795,

%U 807,819,891,894,954,957,990,1047,1059,1062,1191,1269,1350

%N Number of (w,x,y,z) with all terms in {1,...,n} and w^2 = x*y*z.

%C For a guide to related sequences, see A211795.

%H Chai Wah Wu, <a href="/A212062/b212062.txt">Table of n, a(n) for n = 0..10000</a>

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

%t (Do[If[w^2 == x*y*z, s = s + 1],

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

%t Map[t[#] &, Range[0, 50]] (* A212062 *)

%t (* _Peter J. C. Moses_, Apr 13 2012 *)

%Y Cf. A211795.

%K nonn

%O 0,3

%A _Clark Kimberling_, Apr 30 2012

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 5 02:46 EDT 2024. Contains 372257 sequences. (Running on oeis4.)