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Squares that are a sum of two Fibonacci numbers plus the square of a Fibonacci number.
1

%I #20 Mar 30 2012 17:35:07

%S 4,9,16,25,36,49,64,81,100,121,169,225,289,441,676,729,784,1156,1444,

%T 1600,2601,3025,4624,7921,12544,20736,23409,27556,31684,47524,54289,

%U 139129,142129,171396,217156,372100,974169,1488400,2550409,6677056,10201636

%N Squares that are a sum of two Fibonacci numbers plus the square of a Fibonacci number.

%C The squares of A000045 (A007598) are basically a subsequence because they can be expressed as Fibonacci(k+3)^2 = Fibonacci(2k)+Fibonacci(2k+4)+Fibonacci(k-1)^2 or Fibonacci(k+2)^2 = Fibonacci(2k)+Fibonacci(2k+1)+Fibonacci(k)^2 or Fibonacci(2k+3)^2 = Fibonacci(4k)+Fibonacci(4k+4)+Fibonacci(2k-1)^2.

%e a(5)=36=6*6=3+8+25=Fib(4)+Fib(6)+Fib(5)^2.

%Y Cf. A000045, A000290, A179334.

%K nonn

%O 1,1

%A _Carmine Suriano_, Jan 12 2011