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%I #6 Mar 31 2012 20:08:02
%S 18,30,36,42,54,66,78,60,80,102,72,84,138,112,90,184,154,186,452,170,
%T 126,162,196,160,120,150,652,144,692,344,318,376,266,192,200,168,272,
%U 228,304,220,472,426,234,1052,1076,180,474,260,368,722,584,418,534,434
%N Smallest value of x=a+b+c+d (a,b,c,d positive integers) such that there are n different values of m=a^2+b^2=c^2+d^2, or 0 if no such x exists.
%C This is an infinite sequence because if x=4*p (p=any prime), the number of different n values of m is n=k for p=6k+/-1. I do not know if there is an x for every natural number n.
%e We denote m=a^2+b^2=c^2+d^2 by writing (a,b,c,d). Then:
%e x=18->(1,7,5,5)=50 for n=1
%e x=30->(1,12,8,9)=145 (3,11,7,9)=130 for n=2
%e x=36->(2,14,10,10)=200 (3,14,6,13)=205 (4,13,8,11)=185 for n=3
%Y Cf. A091459 A090073.
%K nonn
%O 1,1
%A _Robin Garcia_, Mar 18 2004
%E More terms from _Ray Chandler_, Mar 26 2004
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