A263727 - OEIS

%I #17 Nov 25 2015 02:41:22

%S 0,1,1,1,1,4,4,9,16,25,49,81,144,225,361,576,961,1521,2500,4096,6724,

%T 10816,17689,28561,46225,74529,121104,196249,316969,514089,831744,

%U 1345600,2175625,3523129,5702544,9223369,14922769,24157225,39087504,63234304,102333456

%N Largest square number less than or equal to the n-th Fibonacci number.

%F a(n) = floor(sqrt(Fibonacci(n)))^2.

%F a(n) = A061287(n)^2. - _Michel Marcus_, Oct 25 2015

%F a(n) = A048760(A000045(n)). - _Michel Marcus_, Nov 11 2015

%e For a(8), Fibonacci(8) = 21, the largest square under 21 is 16, so a(8) = 16.

%t Floor[Sqrt[Fibonacci[Range[40]]]]^2 (* _Alonso del Arte_, Oct 24 2015 *)

%o (PARI) a(n) = sqrtint(fibonacci(n))^2; \\ _Michel Marcus_, Oct 25 2015

%Y Cf. A000045, A048760, A061287.

%K nonn,easy

%O 0,6

%A _Eli Jaffe_, Oct 24 2015