A212459 a(n) = ceiling(2n*log(2n)).

2, 6, 11, 17, 24, 30, 37, 45, 53, 60, 69, 77, 85, 94, 103, 111, 120, 130, 139, 148, 157, 167, 177, 186, 196, 206, 216, 226, 236, 246, 256, 267, 277, 287, 298, 308, 319, 330, 340, 351, 362, 373, 384, 395, 405, 417, 428

Offset: 1

Author

Mohammad K. Azarian, May 31 2012

Keywords

• easy
• nonn

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A050502, A050504, A212455, A212456, A212457, A212458, A212460, A212461, A212462.

Programs

Derive

PROG(y := [], x := 100, LOOP(IF(x = 0, RETURN y), y := ADJOIN(CEILING(2·x·LOG(2·x)), y), x := x - 1))

Magma

[Ceiling(2*n*Log(2*n)): n in [1..80]]; // Vincenzo Librandi, Feb 13 2013

Mathematica

Table[Ceiling[2*n*Log[2*n]], {n, 80}] (* Vincenzo Librandi, Feb 13 2013 *)

PARI

a(n) = ceil(2*n*log(2*n)); \\ Michel Marcus, Jan 11 2016

Formula

a(n) = A050502(2*n). - Michel Marcus, Jan 11 2016