A316681 a(n) = floor(n*log(n)/2).

0, 0, 1, 2, 4, 5, 6, 8, 9, 11, 13, 14, 16, 18, 20, 22, 24, 26, 27, 29, 31, 34, 36, 38, 40, 42, 44, 46, 48, 51, 53, 55, 57, 59, 62, 64, 66, 69, 71, 73, 76, 78, 80, 83, 85, 88, 90, 92, 95, 97, 100, 102, 105, 107, 110, 112, 115, 117, 120, 122, 125, 127

Offset

1,4

Links

Table of n, a(n) for n=1..62.

Example

a(1) = floor(1*log(1)/2) = 0;
a(2) = floor(2*log(2)/2) = 0.

Mathematica

Array[Floor[#*Log[#]/2] &, 70] (* Robert G. Wilson v, Jul 21 2018 *)

Prog

(PARI) a(n) = floor(n*log(n)/2); \\ Michel Marcus, Jul 13 2018

Crossrefs

Cf. A050504.

Sequence in context: A099797 A004059 A189404 * A161793 A270970 A188092

Adjacent sequences: A316678 A316679 A316680 * A316682 A316683 A316684

Keyword

nonn,easy

Author

Marcos Librán López, Jul 10 2018

Status

approved