A246390 -id:A246390 - cp's OEIS frontend

A246388 Nonnegative integers k satisfying sin(k) >= 0 and sin(k+1) <= 0.

3, 9, 15, 21, 28, 34, 40, 47, 53, 59, 65, 72, 78, 84, 91, 97, 103, 109, 116, 122, 128, 135, 141, 147, 153, 160, 166, 172, 179, 185, 191, 197, 204, 210, 216, 223, 229, 235, 241, 248, 254, 260, 267, 273, 279, 285, 292, 298, 304, 311, 317, 323, 329, 336, 342

Offset: 0

Clark Kimberling, Aug 24 2014

A246388 and A038130 (Beatty sequence for 2*Pi) partition A022844 (Beatty sequence for Pi). Likewise, A054386, the complement of A022844, is partitioned by A246389 and A246390. (See the Mathematica program.)

Clark Kimberling, Table of n, a(n) for n = 0..1000

Cf. A022844, A038130, A054386, A246389, A246390.

z = 400; f[x_] := Sin[x]
Select[Range[0, z], f[#]*f[# + 1] <= 0 &] (* A022844 *)
Select[Range[0, z], f[#] >= 0 && f[# + 1] <= 0 &]  (* A246388 *)
Select[Range[0, z], f[#] <= 0 && f[# + 1] >= 0 &] (* A038130 *)
Select[Range[0, z], f[#]*f[# + 1] > 0 &] (* A054386 *)
Select[Range[0, z], f[#] >= 0 && f[# + 1] >= 0 &]  (* A246389 *)
Select[Range[0, z], f[#] <= 0 && f[# + 1] <= 0 &] (* A246390 *)

A246389 Nonnegative integers k satisfying sin(k) >= 0 and sin(k+1) >= 0.

Original entry on oeis.org

0, 1, 2, 7, 8, 13, 14, 19, 20, 26, 27, 32, 33, 38, 39, 44, 45, 46, 51, 52, 57, 58, 63, 64, 70, 71, 76, 77, 82, 83, 88, 89, 90, 95, 96, 101, 102, 107, 108, 114, 115, 120, 121, 126, 127, 132, 133, 134, 139, 140, 145, 146, 151, 152, 158, 159, 164, 165, 170, 171

Offset: 0

Clark Kimberling, Aug 24 2014

Clark Kimberling, Table of n, a(n) for n = 0..1000

Cf. A022844, A038130, A054386, A246388, A246390.

Digits := 100:
isA246389 := proc(k)
    if evalf(sin(k)) >= 0 and evalf(sin(k+1)) >= 0 then
        return true ;
    else
        return false ;
    end if;
end proc:
A246389 := proc(n)
    option remember ;
    if n = 1 then
        0;
    else
        for a from procname(n-1)+1 do
            if isA246389(a) then
                return a;
            end if;
        end do:
    end if;
end proc:
seq(A246389(n),n=1..100) ; # assumes offset 1 R. J. Mathar, Jan 18 2024

z = 400; f[x_] := Sin[x]
Select[Range[0, z], f[#]*f[# + 1] <= 0 &] (* A022844 *)
Select[Range[0, z], f[#] >= 0 && f[# + 1] <= 0 &]  (* A246388 *)
Select[Range[0, z], f[#] <= 0 && f[# + 1] >= 0 &] (* A038130 *)
Select[Range[0, z], f[#]*f[# + 1] > 0 &] (* A054386 *)
Select[Range[0, z], f[#] >= 0 && f[# + 1] >= 0 &]  (* A246389 *)
Select[Range[0, z], f[#] <= 0 && f[# + 1] <= 0 &] (* A246390 *)

cp's OEIS Frontend

A246388 Nonnegative integers k satisfying sin(k) >= 0 and sin(k+1) <= 0.

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