A190486 Positions of 2 in A190483.

2, 7, 12, 14, 19, 24, 31, 36, 41, 43, 48, 53, 60, 65, 70, 72, 77, 82, 84, 89, 94, 101, 106, 111, 113, 118, 123, 130, 135, 140, 142, 147, 152, 159, 164, 171, 176, 181, 183, 188, 193, 200, 205, 210, 212, 217, 222, 229, 234, 239, 241, 246, 251, 253, 258, 263, 270, 275, 280, 282, 287, 292, 299, 304, 309, 311, 316

Offset: 1

Author

Clark Kimberling, May 11 2011

Keywords

• nonn

Comments

See A190483.

Links

• G. C. Greubel, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A190483, A190484, A190485.

Programs

Mathematica

r = Sqrt[2]; b = 2; c = 1;
f[n_] := Floor[(b*n + c)*r] - b*Floor[n*r] - Floor[c*r];
t = Table[f[n], {n, 1, 200}]  (* A190483 *)
Flatten[Position[t, 0]]   (* A190484 *)
Flatten[Position[t, 1]]   (* A190485 *)
Flatten[Position[t, 2]]   (* A190486 *)

Python

from sympy import sqrt, floor
r=sqrt(2)
def a190483(n): return floor((2*n + 1)*r) - 2*floor(n*r) - floor(r)
print([n for n in range(1, 501) if a190483(n)==2]) # Indranil Ghosh, Jul 02 2017