A174803 a(n) = n + ceiling(sqrt(n))*floor(sqrt(n)).

0, 2, 4, 5, 8, 11, 12, 13, 14, 18, 22, 23, 24, 25, 26, 27, 32, 37, 38, 39, 40, 41, 42, 43, 44, 50, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 72, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 98, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 128, 137

Offset: 0

Author

Vladimir Joseph Stephan Orlovsky, Mar 29 2010

Keywords

• nonn
• easy

Crossrefs

Cf. A038759, A038760.

Cf. A000290 (n^2), A001105 (2*n^2).

Programs

Mathematica

f[n_]:=n+Floor[Sqrt[n]]*Ceiling[Sqrt[n]];Table[f[n],{n,0,5!}]

Formula

a(n) = n + A038759(n). - Robert G. Wilson v, Apr 17 2010

a(n^2) = 2*n^2. - Bernard Schott, Jul 30 2022