A214080 a(n) = (floor(sqrt(n)))!

1, 1, 1, 1, 2, 2, 2, 2, 2, 6, 6, 6, 6, 6, 6, 6, 24, 24, 24, 24, 24, 24, 24, 24, 24, 120, 120, 120, 120, 120, 120, 120, 120, 120, 120, 120, 720, 720, 720, 720, 720, 720, 720, 720, 720, 720, 720, 720, 720, 5040, 5040, 5040, 5040, 5040, 5040, 5040, 5040, 5040

Offset

0,5

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Formula

Sum_{n>=0} 1/a(n) = 3*e. - Amiram Eldar, Aug 15 2022

a(n) = A000142(A000196(n)). - Michel Marcus, Aug 15 2022

Mathematica

Table[Floor[Sqrt[n]]!, {n, 0, 100}] (* T. D. Noe, Dec 23 2012 *)

Prog

(Derive) PROG(y := [], n := 50, LOOP(IF( = -1, RETURN y), y := ADJOIN(FLOOR(SQRT(n))!, y), n := n - 1))
(Magma) [Factorial(Floor(Sqrt(n))): n in [0..60]]; // Vincenzo Librandi, Feb 13 2013
(PARI) a(n) = floor(sqrt(n))!; \\ Altug Alkan, Jan 11 2016

Crossrefs

Cf. A214078, A214079, A214080, A214081, A214083, A055228, A055226.

Cf. A000142, A000196.

Sequence in context: A338869 A104588 A157279 * A278241 A010671 A339164

Adjacent sequences: A214077 A214078 A214079 * A214081 A214082 A214083

Keyword

easy,nonn

Author

Mohammad K. Azarian, Dec 22 2012

Status

approved