A214079 a(n) = ceiling( n^(1/3) )!.

1, 1, 2, 2, 2, 2, 2, 2, 2, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 120, 120, 120, 120, 120

Offset: 0

Author

Mohammad K. Azarian, Dec 22 2012

Keywords

• easy
• nonn

Links

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

Crossrefs

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

Cf. A000142, A134914.

Programs

Derive

PROG(y := [], x := 70, LOOP(IF(x = -1, RETURN y), y := ADJOIN(CEILING(x^(1/3))!, y), x := x - 1))

Magma

[Factorial(Ceiling(n^(1/3))): n in [0..80]]; // Vincenzo Librandi, Feb 13 2013

Mathematica

Table[Ceiling[n^(1/3)]!, {n, 0, 100}] (* T. D. Noe, Dec 23 2012 *)
Ceiling[Surd[Range[0,70],3]]! (* Harvey P. Dale, Nov 19 2022 *)

PARI

a(n) = ceil(n^(1/3))! \\ Altug Alkan, Jan 11 2016

Formula

Sum_{n>=0} 1/a(n) = 4*e. - Amiram Eldar, Aug 15 2022

a(n) = A000142(A134914(n)). - Michel Marcus, Aug 15 2022