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%I #15 Jan 04 2016 01:54:26
%S 161,189,194,209,234,254,261,270,281,285,290,293,299,321,362,365,369,
%T 371,378,386,390,395,401,405,406,419,429,449,450,465,469,477,482,485,
%U 489,491,501,510,518,534,539,557,563,570,573,574,586,589,601,609,633,644,645,649
%N Numbers that are the sum of 3 distinct nonzero squares in exactly 4 ways.
%H Robert Israel, <a href="/A025342/b025342.txt">Table of n, a(n) for n = 1..3007</a>
%H <a href="/index/Su#ssq">Index entries for sequences related to sums of squares</a>
%p N:= 10^6;
%p A:= Vector(N):
%p for a from 1 to floor(sqrt(N/3)) do
%p for b from a+1 to floor(sqrt((N-a^2)/2)) do
%p c:= [$(b+1) .. floor(sqrt(N-a^2-b^2))]:
%p v:= map(t -> a^2 + b^2 + t^2, c):
%p A[v]:= map(`+`,A[v],1)
%p od od:
%p select(t -> A[t]=4,[$1..N]); # _Robert Israel_, Jan 03 2016
%t Sort[Transpose[Select[Tally[Total/@Subsets[Range[30]^2,{3}]],#[[2]]==4&]][[1]]] (* _Harvey P. Dale_, Apr 24 2013 *)
%K nonn
%O 1,1
%A _David W. Wilson_
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