

A300020


For any k, the cumulative sum a(1) + a(2) + a(3) + ... + a(k) shows at least a digit 6.


1



6, 10, 20, 24, 1, 2, 3, 30, 40, 25, 4, 11, 50, 34, 5, 21, 60, 14, 7, 9, 70, 15, 8, 17, 74, 16, 26, 12, 13, 18, 19, 22, 75, 35, 64, 36, 65, 45, 54, 46, 55, 85, 23, 27, 66, 44, 56, 84, 57, 28, 29, 31, 69, 76, 32, 38, 58, 42, 59, 41, 61, 39, 62, 48, 47, 33, 67, 43, 63, 37, 49, 51, 80, 77, 53, 52
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OFFSET

1,1


COMMENTS

The sequence starts with a(1) = 6 and is always extended with the smallest integer not yet present that does not lead to a contradiction.
A permutation of the natural numbers.


LINKS

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


EXAMPLE

6 shows a digit 6, of course (k = 1)
6 + 10 = 16 and 16 shows at least a digit 6 (k = 2)
6 + 10 + 20 = 36 and 36 shows at least a digit 6 (k = 3)
6 + 10 + 20 + 24 = 60 and 60 shows at least a digit 6 (k = 4)
6 + 10 + 20 + 24 + 1 = 61 and 61 shows at least a digit 6 (k = 5)
6 + 10 + 20 + 24 + 1 + 2 = 63 and 63 shows at least a digit 6 (k = 6)
...


CROSSREFS

Cf. A300015 (which is the lexicographic first sequence of positive integers without duplicate terms having this property).
Sequence in context: A145351 A227874 A015783 * A068017 A270544 A181995
Adjacent sequences: A300017 A300018 A300019 * A300021 A300022 A300023


KEYWORD

nonn,base


AUTHOR

Eric Angelini and JeanMarc Falcoz, Feb 23 2018


STATUS

approved



