A183868 a(n) = n + floor(2*sqrt(n+1)); complement of A079524.

3, 5, 7, 8, 9, 11, 12, 14, 15, 16, 17, 19, 20, 21, 23, 24, 25, 26, 27, 29, 30, 31, 32, 34, 35, 36, 37, 38, 39, 41, 42, 43, 44, 45, 47, 48, 49, 50, 51, 52, 53, 55, 56, 57, 58, 59, 60, 62, 63, 64, 65, 66, 67, 68, 69, 71, 72, 73, 74

Offset: 1

Author

Clark Kimberling, Jan 07 2011

Keywords

• nonn
• easy

Crossrefs

Cf. A079524.

Programs

Maple

A183868 := proc(n) n+floor(2*sqrt(n+1)) ; end proc: # R. J. Mathar, Feb 06 2011

Mathematica

Table[n+Floor[2*Sqrt[n+1]],{n,60}] (* Harvey P. Dale, Nov 05 2013 *)