A282665 The larger term of the pair (a(n), a(n+1)) is always even and the larger digit of any pair of adjacent digits is also even.

0, 2, 1, 4, 3, 6, 5, 8, 7, 80, 20, 22, 12, 14, 16, 18, 24, 21, 26, 28, 34, 36, 38, 40, 42, 41, 44, 43, 46, 48, 56, 58, 60, 62, 61, 64, 63, 66, 65, 68, 78, 82, 81, 84, 83, 86, 85, 88, 87, 800, 200, 202, 120, 204, 121, 206, 122, 124, 126, 128, 140, 208, 141, 212, 142, 144, 143, 400, 214, 146, 148, 160, 216, 161, 218, 162, 164, 163

Offset

1,2

Comments

The sequence is started with a(1) = 0 and always extended with the smallest integer not yet present and not leading to a contradiction. If two successive digits are equal (e.g., 2,2) we accept that there is a "larger one" (2).

Links

Jean-Marc Falcoz, Table of n, a(n) for n = 1..10001

Example

In the 1st pair of integers (0,2) the larger term is (2), which is even;
in the 2nd pair of integers (2,1) the larger term is (2), which is even;
in the 3rd pair of integers (1,4) the larger term is (4), which is even;
in the 4th pair of integers (4,3) the larger term is (4), which is even;
...
in the 9th pair of integers (7,80) the larger term is (80), which is even;
in the 10th pair of integers (80,20) the larger term is (80), which is even;
in the 11th pair of integers (20,22) the larger term is (22), which is even; etc.
In the 1st pair of digits (0,2) the larger digit is (2), which is even;
in the 2nd pair of digits (2,1) the larger digit is (2), which is even;
in the 3rd pair of digits (1,4) the larger digit is (4), which is even;
in the 4th pair of digits (4,3) the larger digit is (4), which is even;
...
in the 9th pair of digits (7,8) the larger digit is (8), which is even;
in the 10th pair of digits (8,0) the larger digit is (8), which is even;
in the 11th pair of digits (0,2) the larger digit is (2), which is even; etc.

Crossrefs

Cf. A282664 (odd rather than even).

Sequence in context: A352726 A317630 A282651 * A320283 A232805 A361740

Adjacent sequences: A282662 A282663 A282664 * A282666 A282667 A282668

Keyword

nonn,base

Author

Eric Angelini and Jean-Marc Falcoz, Feb 20 2017

Status

approved