A022442 a(n) = c(n) + c(n-1) where c is the sequence of numbers not in a.

2, 4, 8, 11, 13, 16, 19, 22, 26, 29, 32, 35, 38, 41, 44, 47, 49, 52, 55, 58, 61, 64, 67, 70, 73, 76, 79, 82, 85, 88, 91, 94, 98, 101, 104, 107, 110, 113, 116, 119, 122, 125, 128, 131, 134, 137

Offset: 0

Author

Clark Kimberling

Keywords

• nonn
• easy

Links

• Ivan Neretin, Table of n, a(n) for n = 0..10000
• R. Stephan, Some divide-and-conquer sequences ...
• R. Stephan, Table of generating functions

Crossrefs

Cf. A099467 (complement).

Cf. A022424 and references therein.

Programs

Mathematica

Fold[Append[#1, Plus @@ Complement[Range[Max@#1 + 3], #1][[{#2 + 1, #2 + 2}]]] &, {2, 4}, Range[44]] (* Ivan Neretin, Mar 30 2017 *)

Formula

For n>0, a(n)=b(n) with b(0)=0, b(2n) = -b(n)+9n+3, b(2n+1) = -b(n)+9n+6-2[n==0]. - Ralf Stephan, Oct 23 2003