A210418 List the positions of all digits 4 in the concatenation of all terms, not necessarily in order. This is the lexicographically earliest such sequence.

2, 4, 5, 44, 7, 40, 11, 41, 14, 17, 42, 21, 43, 24, 27, 45, 31, 46, 34, 37, 47, 54, 444, 4444, 48, 52, 404, 57, 400, 62, 401, 67, 402, 72, 403, 77, 405, 82, 406, 87, 407, 92, 408, 97, 409, 103, 410, 109, 411, 114, 118, 412, 124, 413, 123, 133, 414, 135, 140

Offset

1,1

Comments

See A210415 for comments, links, and code.

Links

Danny Rorabaugh, Table of n, a(n) for n = 1..1000

Example

The sequence cannot start with 1 because the first digit is not 4. Let us start with 2: the second digit is 4. So in the second position we have 4. The third digit cannot be 3 because the third digit is not 4. So let it be 5. In the next position we now have 44. And so on.

Crossrefs

Cf. A210414, A210415, A210416, A210417, A210419, A210420, A210421, A210422, A210423.

Sequence in context: A370438 A303006 A154775 * A167454 A056683 A065574

Adjacent sequences: A210415 A210416 A210417 * A210419 A210420 A210421

Keyword

nonn,base

Author

Paolo P. Lava, Mar 26 2012

Extensions

Name edited and a(22)-a(59) corrected by Danny Rorabaugh, Nov 30 2015

Status

approved