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A109638 A monotonic sequence obeying a different 10-digit rule than A101246. 0
1, 3, 7, 12, 18, 27, 37, 38, 40, 45, 51, 60, 61, 63, 67, 72, 80, 89, 90, 92, 95, 99, 105, 112, 115, 125, 132, 140, 149, 151, 154, 160, 167, 175, 184, 186, 189, 194, 271, 281, 284, 289, 295, 302, 303 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

EXAMPLE

Superimpose sequence and first differences:

Sequence.......: 1 3 7 12 18 27 37 38 40 45 51 60 61 63 67 72 80 89 90

First differences: .2.4.5..6..9..10.1..2..5..6..9..1..2..4..5..8..9..1..

Start with a(1)=1

+ add 2 [which is the smallest integer containing a digit not yet present in the sequence or in the first differences (0 cannot be added as the sequence is monotonic)]:

= we get a(2)=3;

+ add 4 [which is the smallest integer containing a digit not yet present in the sequence or in the first differences]:

= we get a(3)=7

+ add 5 [...]

= we get a(4)=12

+ add 6

= a(5)=18

+ add 9

= a(6)=27

+ add 10

= a(7)=37

We have used now all 10 digits, either in the sequence itself, or in the first differences. Let's introduce the "10-digit chunk" notion:

- the first "10-digit chunk" starts with a(1) and stops immediately after the last of the ten digits we had to include: so the first chunk is made by the (virtual) succession of [1,2,3,4,7,5,12,6,18,9,27,10];

- the second chunk is [37,1,38,2,40,5,45,6,51,9];

- the third chunk is [60,1,61,2,63,4,67,5,72,8,80,9];

- the fourth chunk is [89,1,90,2,92,3,95,4,99,6,105,7];

- ...

- the eighth chunk is [281,3,284,5,289,6,295,7,30]2 (yes, a chunk ends sometimes in the middle of a(n), here a(n)=302] -- thus the next chunk will also start in the middle of that a(n): [2,1,303...]

- etc.

CROSSREFS

Sequence in context: A169679 A024388 A184534 * A008332 A065390 A171835

Adjacent sequences:  A109635 A109636 A109637 * A109639 A109640 A109641

KEYWORD

base,easy,nonn

AUTHOR

Eric Angelini (eric.angelini(AT)kntv.be), Aug 30 2005

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Last modified February 17 23:46 EST 2012. Contains 206085 sequences.