A321797 Delete the decimal digits of n that appear exactly once; write 0 if all digits disappear.

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 11, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 22, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 33, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 44, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 55, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 66, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 77, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 88, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 99, 0, 11, 0, 0, 0, 0, 0, 0, 0, 0, 11, 111, 11, 11, 11, 11, 11, 11, 11, 11, 0, 11, 22, 0, 0, 0, 0, 0, 0, 0, 0, 11, 0, 33, 0, 0, 0, 0, 0, 0, 0, 11, 0, 0, 44, 0, 0, 0, 0, 0, 0, 11, 0, 0, 0, 55, 0, 0, 0, 0, 0, 11, 0, 0, 0, 0, 66, 0, 0, 0, 0, 11, 0, 0, 0, 0, 0, 77, 0, 0, 0, 11, 0, 0, 0, 0, 0, 0, 88, 0, 0, 11, 0, 0, 0, 0, 0, 0, 0, 99

Offset

0,12

Comments

A companion sequence to A320486.

Digits that appear exactly once in n are erased. Leading zeros are erased unless the result is 0. If all digits are erased, we write 0 for the result (A321800 is another version, which uses -1 for the empty string).

More than the usual number of terms are shown in order to reach some interesting examples.

Links

Chai Wah Wu, Table of n, a(n) for n = 0..10000

Example

12321 becomes 1221, 1123 becomes 11, 11231 becomes 111, and 100223 becomes 22 (as we don't accept leading zeros). Note that 12345 disappears immediately and we get 0.

Prog

(Python)
def A321797(n):
    return int('0'+''.join(d if str(n).count(d) != 1 else '' for d in str(n)))

Crossrefs

Cf. A320486, A321800.

Sequence in context: A279540 A321538 A321803 * A113043 A110408 A377778

Adjacent sequences: A321794 A321795 A321796 * A321798 A321799 A321800

Keyword

nonn,base

Author

Chai Wah Wu, Nov 19 2018

Status

approved