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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A155817 Sequence having the property that a(n) is the sum of the first a(n) digits of the sequence 2
1, 10, 2, 4, 100, 101, 11, 12, 13, 14, 30, 1000, 10000, 40, 41, 100000, 102, 43, 60, 110, 1000000, 1001, 61, 80, 111, 100000000000, 90, 10000000, 103, 104, 10001, 1110, 112, 201, 108, 91, 95, 160, 161, 100000000000000000000000000000000000, 170, 1000001 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

From an idea of Eric Angelini (eric.angelini(AT)kntv.be). The condition of strict monotonicity is dropped with respect to A154328.

LINKS

Jon Schoenfield, Table of n, a(n) for n = 1..1000

EXAMPLE

We start with a(1)=1. The next term a(2) cannot be 2,...,9 because the sum of these digits would be larger: the least possibility not leading to a contradiction is a(2)=10. Then we can go on with a(3)=2 because the sum of the first two digits, 1=a(1) and 1 from 10=a(2), is equal to 2. Then a(4)=4 because sum of the first 4 digits, 1+1+0+2, is equal to 4.

CROSSREFS

Cf. A154328

Sequence in context: A169851 A161995 A069036 * A037922 A111287 A084455

Adjacent sequences:  A155814 A155815 A155816 * A155818 A155819 A155820

KEYWORD

nonn,base

AUTHOR

Paolo P. Lava (paoloplava(AT)gmail.com), Jan 28 2009

EXTENSIONS

Sequence corrected and extended by N. J. A. Sloane, Aug 31 2009, using terms from the b-file.

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

Content is available under The OEIS End-User License Agreement .

Last modified February 14 11:14 EST 2012. Contains 205619 sequences.