A273864 The successive numbers of digits visible between two even terms are given by the sequence itself.

0, 2, 1, 3, 4, 5, 6, 7, 11, 8, 9, 101, 10, 13, 103, 12, 15, 17, 19, 14, 21, 23, 105, 16, 25, 27, 29, 31, 107, 18, 33, 35, 37, 39, 20, 41, 43, 45, 109, 22, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 75, 77, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 1001, 24, 139, 141, 1003, 26, 143, 145, 147, 1005, 28, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189

Offset

1,2

Comments

The sequence starts with a(1)=0. It is then extended with the smallest integer not yet present and not leading to a contradiction.

Links

Table of n, a(n) for n=1..113.

Example

The first two even terms that appear in the sequence are 0 and 2; between 0 and 2 there are 0 digits and this 0 corresponds to the starting 0 of the sequence.
The next even term is 4 and between 2 and 4 there are 2 digits [which are 1 and 3] and this 2 corresponds to the next term of the sequence.
The next even term is 6 and between 4 and 6 there is 1 digit [which is 5] and this 1 corresponds to the next term of the sequence.
The next even term is 8 and between 6 and 8 there are 3 digits [which are 7, 1 and 1] and this 3 corresponds to the next term of the sequence.
The next even term is 10 and between 8 and 10 there are 4 digits [which are 9, 1, 0 and 1] and this 4 corresponds to the next term of the sequence.
Etc.

Crossrefs

Sequence in context: A155963 A375326 A273863 * A058684 A226054 A109920

Adjacent sequences: A273861 A273862 A273863 * A273865 A273866 A273867

Keyword

nonn,base

Author

Eric Angelini, Jun 01 2016

Status

approved