

A137564


The number formed by removing from n all duplicate digits except the leftmost copy of each.


4



0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 2, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 3, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 4, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 5, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 6, 67, 68, 69, 70, 71, 72, 73, 74
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OFFSET

0,3


COMMENTS

a(n)=n iff n is a term of A010784. a(n)<n iff n is a term of A109303.


LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 0..10000


EXAMPLE

a(100)=10 as a (second) 0 digit is dropped. a(100) is the first term differing from A106612's terms: A106612(100)=100. a(1211323171)=1237.


MATHEMATICA

Table[FromDigits@ DeleteDuplicates@ IntegerDigits@ n, {n, 74}] (* Michael De Vlieger, Jun 01 2016 *)


PROG

(Haskell)
a137564 = f (1) where
f _ 0 = 0
f r x = if d == r then f r x' else 10 * f d x' + d
where (x', d) = divMod x 10
 Reinhard Zumkeller, Jan 28 2015


CROSSREFS

Cf. A106612, A010784, A109303.
Sequence in context: A180409 A320485 A321802 * A106612 A056960 A227362
Adjacent sequences: A137561 A137562 A137563 * A137565 A137566 A137567


KEYWORD

base,easy,nonn


AUTHOR

Rick L. Shepherd, Jan 25 2008


STATUS

approved



