A195119 a(n) = 2*n - floor(n*sqrt(2)).

0, 1, 2, 2, 3, 3, 4, 5, 5, 6, 6, 7, 8, 8, 9, 9, 10, 10, 11, 12, 12, 13, 13, 14, 15, 15, 16, 16, 17, 17, 18, 19, 19, 20, 20, 21, 22, 22, 23, 23, 24, 25, 25, 26, 26, 27, 27, 28, 29, 29, 30, 30, 31, 32, 32, 33, 33, 34, 34, 35, 36, 36, 37, 37, 38, 39, 39, 40, 40, 41, 42, 42

Offset: 0

Author

Clark Kimberling, Sep 09 2011

Keywords

• nonn
• easy

Comments

Not A077467, which has only one 17; not A098294, which has two 41's.

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A005843 (2n), A001951 (floor(n*sqrt(2))).

Programs

Magma

[2*n-Floor(n*Sqrt(2)): n in [0..70]]; // Vincenzo Librandi, Sep 12 2011

Maple

seq(2*n-floor(n*sqrt(2)),n=0..80); # Muniru A Asiru, Sep 30 2018

Mathematica

Table[2*n - Floor[n*Sqrt[2]], {n,0,100}] (* G. C. Greubel, Sep 29 2018 *)

PARI

vector(100, n, n--; 2*n-floor(n*sqrt(2))) \\ G. C. Greubel, Sep 29 2018

Formula

a(n) = A005843(n) - A001951(n). - Michel Marcus, Sep 30 2018