Square root of the five-tuples used in S000491.
5, 4, 2, 2, 1, 7, 4, 4, 4, 1, 10, 7, 7, 1, 1, 13, 11, 4, 4, 4, 30, 29, 7, 3, 1, 50, 47, 11, 11, 7, 77, 76, 11, 4, 4, 174, 123, 123, 3, 3
1
The first two numbers in each 5-tuple are usually so close that the plot points appear the same.
T. D. Noe, Plot of 8 5-tuples
Eric W. Weisstein, MathWorld: Lucas Number
(Mma) nn = 51; PerfectSquareQ[n_] := JacobiSymbol[n, 13] =!= -1 && JacobiSymbol[n, 19] =!= -1 && JacobiSymbol[n, 17] =!= -1 && JacobiSymbol[n, 23] =!= -1 && IntegerQ[Sqrt[n]]; l2 = Table[LucasL[n]^2, {n, 0, nn}]; t = {}; Do[If[a >= b >= c >= d && (a != b || a != c || a != d || b != c || b != d || c != d), n = a + b + c + d; If[PerfectSquareQ[n], AppendTo[t, {n, a, b, c, d}]]], {a, l2}, {b, l2}, {c, l2}, {d, l2}]; Sqrt[t]
nonn
T. D. Noe, Feb 24 2015