

A098645


List the positions of all digits '1' in the sequence. This is the lexicographically earliest increasing sequence with this property.


12



1, 3, 10, 20, 22, 31, 32, 33, 34, 35, 41, 51, 52, 53, 54, 55, 111, 112, 200, 210, 220, 222, 231, 1111, 2000, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2020, 2022, 2023, 2024, 2031, 10000, 20000, 20002, 20003, 20004, 20005, 20006, 20007, 20008, 20009
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OFFSET

1,2


COMMENTS

Start with a(1) = 1. For n > 1, choose a(n) to be the smallest number > a(n1) consistent with the condition that "the a(n)th digit is a 1 and no 1's occur in other positions" is true for all n.
If we change "> a(n1)" to "not already used", we get 1, 3, 10, 6, 11, 7, 21, 13, 15, 17, 19, 101, ...  David Wasserman, Feb 26 2008
That sequence has by now been entered as A210415.  M. F. Hasler, Oct 08 2013


LINKS

Table of n, a(n) for n=1..48.
Index to the OEIS: Entries related to selfreferencing sequences.


EXAMPLE

The first digit of the sequence is a "1", the 3rd digit also, then the 10th, the 11th, etc.


CROSSREFS

Cf. A098670. See A114134 for another version. See also A210414A210423.
Sequence in context: A048343 A056789 A174476 * A089693 A194116 A208951
Adjacent sequences: A098642 A098643 A098644 * A098646 A098647 A098648


KEYWORD

base,easy,nonn


AUTHOR

Eric Angelini, Oct 27 2004


EXTENSIONS

Entry revised by Eric Angelini and N. J. A. Sloane, Feb 03 2006.
More terms from David Wasserman, Feb 26 2008


STATUS

approved



