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A257831 In decimal representation of n: replace each digit with its binary representation. 2
0, 1, 10, 11, 100, 101, 110, 111, 1000, 1001, 10, 11, 110, 111, 1100, 1101, 1110, 1111, 11000, 11001, 100, 101, 1010, 1011, 10100, 10101, 10110, 10111, 101000, 101001, 110, 111, 1110, 1111, 11100, 11101, 11110, 11111, 111000, 111001, 1000, 1001, 10010, 10011 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

a(n) = n iff (largest digit of n) = 1: a(A007088(n)) = A007088(n);

a(n) = A007088(A080719(n)).

LINKS

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

EXAMPLE

.    n |  dec    -->  bin         |     a(n) |  A080719(n)

. -----+--------------------------+----------+------------

.  100 |  [1,0,0]  |  [1,0,0]     |     100  |          4

.  101 |  [1,0,1]  |  [1,0,1]     |     101  |          5

.  102 |  [1,0,2]  |  [1,0,10]    |    1010  |         10

.  103 |  [1,0,3]  |  [1,0,11]    |    1011  |         11

.  104 |  [1,0,4]  |  [1,0,100]   |   10100  |         20

.  105 |  [1,0,5]  |  [1,0,101]   |   10101  |         21

.  106 |  [1,0,6]  |  [1,0,110]   |   10110  |         22

.  107 |  [1,0,7]  |  [1,0,111]   |   10111  |         23

.  108 |  [1,0,8]  |  [1,0,1000]  |  101000  |         40

.  109 |  [1,0,9]  |  [1,0,1001]  |  101001  |         41

.  110 |  [1,1,0]  |  [1,1,0]     |     110  |          6

.  111 |  [1,1,1]  |  [1,1,1]     |     111  |          7

.  112 |  [1,1,2]  |  [1,1,10]    |    1110  |         14

.  113 |  [1,1,3]  |  [1,1,11]    |    1111  |         15

.  114 |  [1,1,4]  |  [1,1,100]   |   11100  |         28

.  115 |  [1,1,5]  |  [1,1,101]   |   11101  |         29

.  116 |  [1,1,6]  |  [1,1,110]   |   11110  |         30

.  117 |  [1,1,7]  |  [1,1,111]   |   11111  |         31

.  118 |  [1,1,8]  |  [1,1,1000]  |  111000  |         56

.  119 |  [1,1,9]  |  [1,1,1001]  |  111001  |         57

.  120 |  [1,2,0]  |  [1,10,0]    |    1100  |         12

.  121 |  [1,2,1]  |  [1,10,1]    |    1101  |         13

.  122 |  [1,2,2]  |  [1,10,10]   |   11010  |         26

.  123 |  [1,2,3]  |  [1,10,11]   |   11011  |         27

.  124 |  [1,2,4]  |  [1,10,100]  |  110100  |         52

.  125 |  [1,2,5]  |  [1,10,101]  |  110101  |         53  .

PROG

(Haskell)

import Data.Maybe (mapMaybe)

a257831 = foldr (\b v -> 10 * v + b) 0 .

           concat . mapMaybe (flip lookup bin) . a031298_row

            where bin = zip [0..9] a030308_tabf

(Python)

def A257831(n):

....return int(''.join((format(int(d), 'b') for d in str(n))))

# Chai Wah Wu, May 10 2015

CROSSREFS

Cf. A007088, A030308, A031298, A080719.

Sequence in context: A303605 A266946 A081551 * A007088 A115848 A136814

Adjacent sequences:  A257828 A257829 A257830 * A257832 A257833 A257834

KEYWORD

nonn,base

AUTHOR

Reinhard Zumkeller, May 10 2015

STATUS

approved

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Last modified October 24 00:04 EDT 2018. Contains 316541 sequences. (Running on oeis4.)