A022431 - OEIS

A022431

a(n) = c(n-1) + c(n-3) where c is the sequence of numbers not in a.

1, 2, 7, 8, 10, 14, 17, 21, 24, 27, 29, 33, 35, 38, 41, 43, 47, 49, 53, 56, 59, 62, 65, 68, 71, 75, 77, 81, 84, 87, 90, 93, 96, 99, 102, 105, 107, 111, 113, 117, 119, 123, 125, 129, 131, 135

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

LINKS

Ivan Neretin, Table of n, a(n) for n = 0..10000

MATHEMATICA

Fold[Append[#1, Plus @@ Complement[Range[Max@#1 + 3], #1][[{#2, #2 + 2}]]] &, {1, 2, 7}, Range[43]] (* Ivan Neretin, Mar 29 2017 *)

CROSSREFS

Cf. A022424 and references therein.

Sequence in context: A168064 A243167 A039005 * A356671 A047525 A075766

Adjacent sequences: A022428 A022429 A022430 * A022432 A022433 A022434

KEYWORD

nonn

AUTHOR

Clark Kimberling

STATUS

approved