login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A098645 List the positions of all digits '1' in the sequence. This is the smallest possible 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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Start with a(1) = 1. For n > 1, choose a(n) to be the smallest number > a(n-1) 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(n-1)" 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 self-referencing 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 A210414-A210423.

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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 23 03:21 EDT 2018. Contains 316519 sequences. (Running on oeis4.)