

A284030


Replacing each term with its digital root generates the original sequence, digit by digit.


1



1, 2, 3, 4, 5, 6, 7, 8, 9, 19, 18, 28, 17, 11, 26, 37, 16, 46, 55, 29, 15, 12, 25, 64, 24, 13, 33, 14, 23, 38, 27, 73, 32, 82, 47, 56, 41, 42, 22, 65, 31, 91, 21, 39, 48, 118, 49, 74, 57, 66, 35, 83, 34, 43, 75, 84, 92, 44, 119, 58, 52, 59, 51, 67, 127, 76, 128, 137, 146, 69, 68, 93, 136, 36, 145, 155, 154, 111, 45, 85, 53, 163, 172, 62, 94, 54, 61, 112, 77, 79, 78, 87, 129, 86, 71, 138, 147
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OFFSET

1,2


COMMENTS

The sequence is started with a(1) = 1 and always extended with the smallest integer not yet present and not leading to a contradiction.
There is no digit "0" in the sequence as "0" cannot be a digital root.


LINKS

JeanMarc Falcoz, Table of n, a(n) for n = 1..10001


EXAMPLE

After 1,2,3,4,5,6,7,8,9 we have the terms 19,18,28,17,11,26,37,16,46,55,..., whose digital roots are respectively 1,9,1,8,2,8,1,7,1,1,... These digits are precisely the ones used in the sequence, in that order.


CROSSREFS

Cf. A010888 (digital root), A052382 (zeroless numbers).
Sequence in context: A118758 A174025 A106649 * A087121 A087052 A077557
Adjacent sequences: A284027 A284028 A284029 * A284031 A284032 A284033


KEYWORD

base,nonn


AUTHOR

Eric Angelini and JeanMarc Falcoz, Mar 24 2017


STATUS

approved



