A183574 n+Floor[sqrt(2n+2)].

3, 4, 5, 7, 8, 9, 11, 12, 13, 14, 15, 17, 18, 19, 20, 21, 23, 24, 25, 26, 27, 28, 29, 31, 32, 33, 34, 35, 36, 37, 39, 40, 41, 42, 43, 44, 45, 46, 47, 49, 50, 51, 52, 53, 54, 55, 56, 57, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92

Offset: 1

Author

Clark Kimberling, Jan 05 2011

Keywords

• nonn
• easy

Crossrefs

Cf. A183575, the complement of A183574.

Programs

Mathematica

a=2;b=2; Table[n+Floor[(a*n+b)^(1/2)],{n,80}]

Formula

a(n)=n+Floor[sqrt(2n+2)].