A305849 Positions of 2 in the difference sequence of A305847.

3, 6, 9, 11, 14, 17, 19, 22, 25, 27, 30, 32, 35, 38, 40, 43, 46, 48, 51, 53, 56, 59, 61, 64, 67, 69, 72, 74, 77, 80, 82, 85, 87, 90, 93, 95, 98, 101, 103, 106, 108, 111, 114, 116, 119, 122, 124, 127, 129, 132, 135, 137, 140, 142, 145, 148, 150, 153, 156, 158

Offset

1,1

Comments

This is also the sequence of positions of 3 in the difference sequence of A305848.

Links

Clark Kimberling, Table of n, a(n) for n = 1..3000

Example

A305837 = (1,2,3,5,6,7,9,10,11,13,14,16, ...);
differences: (1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 2, 1, 1, 2, 1, 1, 2, 1, 2, ...);
positions of 2: (3,6,9,11,14, ...).

Mathematica

mex[list_, start_] := (NestWhile[# + 1 &, start, MemberQ[list, #] &]);
u = 5; v = 5; z = 220;
c = {v}; a = {1}; b = {Last[c] - Last[a]};
Do[AppendTo[a, mex[Flatten[{a, b}], Last[a]]];
  AppendTo[c, u Length[c] + v];
  AppendTo[b, Last[c] - Last[a]], {z}];
c = Flatten[Position[Differences[a], 2]];
a  (* A305847 *)
b  (* A305848 *)
c  (* A305849 *)
(* Peter J. C. Moses, May 30 2018 *)

Crossrefs

Cf. A001622, A305847, A305848.

Sequence in context: A223731 A223732 A094740 * A047400 A054414 A136616

Adjacent sequences: A305846 A305847 A305848 * A305850 A305851 A305852

Keyword

nonn,easy

Author

Clark Kimberling, Jun 11 2018

Status

approved