A248419 Numbers k such that A248418(k+1) = A248418(k).

4, 6, 8, 10, 12, 14, 15, 17, 18, 20, 21, 23, 24, 26, 27, 29, 30, 31, 33, 34, 35, 37, 38, 39, 41, 42, 43, 45, 46, 47, 49, 50, 51, 52, 54, 55, 56, 57, 59, 60, 61, 62, 64, 65, 66, 67, 69, 70, 71, 72, 74, 75, 76, 77, 79, 80, 81, 82, 83, 85, 86, 87, 88, 89, 91

Offset

1,1

Comments

Complement of A248420.

Links

Clark Kimberling, Table of n, a(n) for n = 1..1000

Example

A248418 = (1, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 0, 1, ...), so that A248419 = (4,6,8,10,12,14,15, ...) and A248420 = (1, 2, 3, 5, 7, 9, 11, 13, 16, 19, 22, 25, ...).

Mathematica

z = 550; p[k_] := p[k] = k*Tan[Pi/k]; N[Table[p[n] - Pi, {n, 3, z/10}]]
f[n_] := f[n] = Select[2 + Range[z], p[#] - Pi < 1/n &, 1];
u = Flatten[Table[f[n], {n, 3, z}]]  (* A248418 *)
Differences[u]
v = Flatten[Position[Differences[u], 0]]    (* A248419 *)
w = Flatten[Position[Differences[u], 1]]    (* A248420 *)
g = Table[Floor[1/(p[n] - Pi)], {n, 3, z}]  (* A248421 *)

Crossrefs

Cf. A248418, A248420, A248421.

Sequence in context: A322368 A078941 A078942 * A186389 A039767 A176235

Adjacent sequences: A248416 A248417 A248418 * A248420 A248421 A248422

Keyword

nonn,easy

Author

Clark Kimberling, Oct 07 2014

Status

approved