A114308 Self-describing sequence: sequence starts with a(1) = 1 and a(n) is chosen to be the smallest number > a(n-1) such that the assertion "sequence gives the positions of the odd digits when the sequence is read as a string of digits" is true.

1, 4, 6, 7, 8, 9, 11, 12, 13, 16, 21, 22, 24, 31, 41, 42, 44, 46, 50, 60, 62, 64, 66, 71, 81, 83, 84, 85, 86, 88, 200, 201, 210, 301, 400, 410, 420, 422, 423, 431, 510, 520, 600, 602, 604, 606, 608, 620, 622, 624, 626, 628, 640, 642, 644, 646, 648, 660

Offset: 1

Author

Eric Angelini, Feb 05 2006

Keywords

• base
• easy
• nonn

Examples

			Brackets indicate the odd digits in the sequence:
Sequence: (1),4,6,(7),8,(9),(1)(1),(1)2, (1)(3),(1)6
Positions of odd digits: 1st 4th 6th 7th 8th 9th 11th 12th 13th ..., which is the sequence itself.
		

Links

• N. J. A. Sloane, Table of n, a(n) for n = 1..480

Crossrefs

Cf. A125132.

Extensions

More terms from N. J. A. Sloane, Jan 10 2007