A184113 n + floor(4*sqrt(n+1)).

6, 8, 11, 12, 14, 16, 18, 20, 21, 23, 24, 26, 27, 29, 31, 32, 33, 35, 36, 38, 39, 41, 42, 44, 45, 46, 48, 49, 50, 52, 53, 54, 56, 57, 59, 60, 61, 62, 64, 65, 66, 68, 69, 70, 72, 73, 74, 76, 77, 78, 79, 81, 82, 83, 84, 86, 87, 88, 89, 91, 92, 93, 95, 96, 97, 98, 99, 101, 102, 103, 104, 106, 107, 108, 109, 111, 112, 113, 114, 116, 117, 118, 119, 120, 122, 123, 124, 125, 126, 128, 129, 130, 131, 132, 134, 135, 136, 137, 139, 140

Offset: 1

Author

Clark Kimberling, Jan 09 2011

Keywords

• nonn
• easy

Crossrefs

Cf. A184102.

Programs

Mathematica

a=16; b=16; Table[n+Floor[(a*n+b)^(1/2)],{n,100}]

Formula

a(n) = n + floor(4*sqrt(n+1))