A248420 Numbers k such that A248418(k+1) = A248418(k) + 1.

1, 2, 3, 5, 7, 9, 11, 13, 16, 19, 22, 25, 28, 32, 36, 40, 44, 48, 53, 58, 63, 68, 73, 78, 84, 90, 96, 102, 109, 116, 123, 130, 137, 144, 152, 160, 168, 176, 184, 193, 202, 211, 220, 229, 239, 249, 259, 269, 279, 290, 301, 311, 323, 334, 345, 357, 369, 381, 393, 406, 419, 431, 445, 458, 471, 485, 499, 513, 527, 541

Offset

1,2

Comments

Complement of A248419.

Links

Clark Kimberling, Table of n, a(n) for n = 1..100

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, A248419, A248421.

Sequence in context: A186390 A022554 A097046 * A011861 A229511 A305078

Adjacent sequences: A248417 A248418 A248419 * A248421 A248422 A248423

Keyword

nonn,easy

Author

Clark Kimberling, Oct 07 2014

Status

approved