S000487


Squares that are the sum of 4 different squares of Fibonacci numbers.

1225, 8100, 54756, 164025, 373321, 2553604, 17489124, 119836809, 821280964, 5628900676, 38580423561, 264432492900, 1812442912900, 12422657127241, 85146128781156, 583600170521124, 4000054871604169, 27416783424740164, 187917427776935844

1

S000487

That is, s^2 = f1^2 + f2^2 + f3^2 + f4^2, where the fi are Fibonacci numbers all different.

T. D. Noe, Plot of 48 terms

T. D. Noe, Table of 48 terms

Eric W. Weisstein, MathWorld: Fibonacci Number

(Mma) nn = 41; PerfectSquareQ[n_] := JacobiSymbol[n, 13] =!= -1 && JacobiSymbol[n, 19] =!= -1 && JacobiSymbol[n, 17] =!= -1 && JacobiSymbol[n, 23] =!= -1 && IntegerQ[Sqrt[n]]; f2 = Table[Fibonacci[n]^2, {n, 2, nn}]; t = {}; Do[If[a > b > c > d, n = a + b + c + d; If[PerfectSquareQ[n], AppendTo[t, n]]], {a, f2}, {b, f2}, {c, f2}, {d, f2}]; t

Cf. S000481-S000490.

nonn,tabl

T. D. Noe, Feb 18 2015

© Tony D Noe 2014-2015