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A024804 Numbers that are the sum of 3 distinct nonzero squares in 2 or more ways. 3

%I

%S 62,69,74,77,86,89,90,94,98,101,105,110,117,122,125,126,129,131,134,

%T 138,141,146,149,150,154,155,158,161,165,166,170,173,174,179,181,182,

%U 185,186,189,194,195,197,201,203,206,209,210,213,217,218,221,222,225,227,229,230

%N Numbers that are the sum of 3 distinct nonzero squares in 2 or more ways.

%H <a href="/index/Su#ssq">Index entries for sequences related to sums of squares</a>

%F {n: A025442(n) >= 2}.

%p isA024804 := proc(n) local ws; ws := 0 ; for x from 1 do if x^2 > n then break; end if; for y from x+1 do if x^2+y^2>n then break; end if; z := n-x^2-y^2 ; if issqr(z) then z := sqrt(z) ; if z > y then ws := ws+1 ; end if; end if ; end do: end do: ws >= 2 ; end proc:

%p for n from 1 to 230 do if isA024804(n) then printf("%d,",n) ; end if; end do: # _R. J. Mathar_, Dec 07 2010

%t nn=230; t=Table[0, {nn}]; Do[n=i^2+j^2+k^2; If[n<=nn, t[[n]]++], {i, Sqrt[nn]}, {j, i+1, Sqrt[nn]}, {k, j+1, Sqrt[nn]}]; Flatten[Position[t, _?(#>1&)]]

%K nonn

%O 1,1

%A _Clark Kimberling_

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Last modified November 22 13:47 EST 2019. Contains 329393 sequences. (Running on oeis4.)