

A331879


Lexicographically earliest sequence of distinct positive integers such that (last digit of a(n)) < (first digit of a(n+1)).


2



1, 2, 3, 4, 5, 6, 7, 8, 90, 10, 11, 20, 12, 30, 13, 40, 14, 50, 15, 60, 16, 70, 17, 80, 18, 91, 21, 22, 31, 23, 41, 24, 51, 25, 61, 26, 71, 27, 81, 28, 92, 32, 33, 42, 34, 52, 35, 62, 36, 72, 37, 82, 38, 93, 43, 44, 53, 45, 63, 46, 73, 47, 83, 48, 94, 54, 55, 64, 56, 74, 57, 84, 58, 95, 65, 66, 75, 67, 85
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OFFSET

1,2


COMMENTS

No integer ending in 9 is a member of the sequence (by definition).


LINKS

Carole Dubois, Table of n, a(n) for n = 1..20000


EXAMPLE

a(8) = 8 and 8 (the last digit) is < 9, this 9 being the first digit of a(9) = 90
a(9) = 90 and 0 (the last digit) is < 1, this 1 being the first digit of a(10) = 10
a(10) = 10 and 0 (the last digit) is < 1, this 1 being the first digit of a(11 = 11
a(11) = 11 and 1 (the last digit) is < 2, this 2 being the first digit of a(12) = 2; etc.


CROSSREFS

Cf. A331880 for the variant where the last digit of a(n) is > than the first digit of a(n+1).
Sequence in context: A171679 A044910 A109752 * A098755 A028430 A290148
Adjacent sequences: A331876 A331877 A331878 * A331880 A331881 A331882


KEYWORD

base,nonn


AUTHOR

Eric Angelini and Carole Dubois, Jan 30 2020


STATUS

approved



