A065731 Greatest perfect square that does not exceed n!.

1, 1, 1, 4, 16, 100, 676, 4900, 40000, 362404, 3625216, 39904489, 478996996, 6226945921, 87177877081, 1307672296225, 20922784184449, 355687416544329, 6402373660047556, 121645099966283776, 2432902006216007824, 51090942169052381124, 1124000727752683686724

Offset

0,4

Links

Harry J. Smith, Table of n, a(n) for n = 0..100

Formula

a(n) = floor(sqrt(n!))^2.

Mathematica

Array[Floor@ Sqrt[#!]^2 &, 21, 0] (* Michael De Vlieger, Dec 06 2018 *)

Prog

(PARI) { for (n=0, 100, a=sqrtint(n!)^2; write("b065731.txt", n, " ", a) ) } \\ Harry J. Smith, Oct 28 2009
(Magma) [Floor(Sqrt(Factorial(n)))^2: n in [0..25]]; // Vincenzo Librandi, Dec 07 2018

Crossrefs

a(n) = A048760(A000142(n)).

Cf. A048760, A000142, A065730-A065741.

Sequence in context: A121142 A318693 A087296 * A074187 A111883 A370529

Adjacent sequences: A065728 A065729 A065730 * A065732 A065733 A065734

Keyword

easy,nonn

Author

Labos Elemer, Nov 15 2001

Extensions

Offset changed from 1 to 0 by Harry J. Smith, Oct 28 2009

Status

approved