A333301 a(1) = 1, a(2) = 2. For n>2, if a(n-1) is odd, a(n) = a(n-1) + a(n-2), and otherwise a(n) is the smallest missing number.

1, 2, 3, 5, 8, 4, 6, 7, 13, 20, 9, 29, 38, 10, 11, 21, 32, 12, 14, 15, 29, 44, 16, 17, 33, 50, 18, 19, 37, 56, 22, 23, 45, 68, 24, 25, 49, 74, 26, 27, 53, 80, 28, 30, 31, 61, 92, 34, 35, 69, 104, 36, 39, 75, 114, 40, 41, 81, 122, 42, 43, 85, 128, 46, 47, 93, 140, 48, 51, 99, 150, 52, 54, 55, 109, 164

Offset: 1

Author

Andrew Slattery, Jun 08 2020

Keywords

• nonn
• easy

Comments

How many times does each number appear?

Examples

			a(10) is even, so a(11) is the least number yet to appear, which is 9.
		

Crossrefs

Cf. A069202, A307023.