A309390 Set a(1)=10. Thereafter a(n) is the smallest positive number not yet in the sequence that contains exactly one even digit and one odd digit from a(n-1).

10, 100, 101, 102, 12, 21, 112, 120, 103, 30, 130, 104, 14, 41, 114, 124, 121, 122, 123, 23, 32, 132, 125, 25, 52, 152, 126, 16, 61, 106, 105, 50, 150, 107, 70, 170, 108, 18, 81, 118, 128, 127, 27, 72, 172, 129, 29, 92, 192, 142, 134, 34, 43, 143, 140, 109, 90, 190, 110, 160, 116

Offset: 1

Author

Enrique Navarrete, Jul 27 2019

Keywords

• nonn
• base

Comments

Numbers such as 3, 8, 20, 31, and 42 are not in the sequence since by definition all terms must contain both odd and even digits.

Examples

			a(2)=100 since it is the smallest number not yet in the sequence that contains an even digit (0) and an odd digit (1) from a(1)=10.
a(7)=112 since it is the smallest number not yet in the sequence that contains an even digit (2) and an odd digit (1) from a(6)=21.
a(27)=126 is not 105 since 105 would contain two odd digits (1 and 5) from a(26)=152.
		

Crossrefs

Cf. A318700 (positive numbers that contain both odd and even digits).