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A298359
Lexicographically earliest sequence of distinct positive terms such that, for any n > 0, Sum_{k = 1..n} 10^(k-1) * a(k) can be computed without carry in decimal base.
2
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 20, 21, 22, 23, 24, 25, 26, 27, 30, 31, 32, 33, 34, 35, 36, 40, 41, 42, 43, 44, 45, 50, 51, 52, 53, 54, 60, 61, 62, 63, 70, 71, 72, 80, 81, 90, 100, 19, 37, 46, 55, 64, 73, 82, 91, 110, 28, 56, 74
OFFSET
1,2
COMMENTS
More informally: write the terms in decimal under each other, right-justified; the digits on each diagonal in downwards direction sum at most to 9.
The corresponding sequence for base 2 is A094958.
See also A298425 for a similar sequence.
LINKS
EXAMPLE
The first terms, alongside 10^(n-1) * a(n), are:
n a(n) 10^(n-1) * a(n)
-- ---- -------------------
1 1 1
2 2 20
3 3 300
4 4 4000
5 5 50000
6 6 600000
7 7 7000000
8 8 80000000
9 9 900000000
10 10 10000000000
11 11 110000000000
12 12 1200000000000
13 13 13000000000000
14 14 140000000000000
15 15 1500000000000000
16 16 16000000000000000
17 17 170000000000000000
18 18 1800000000000000000
19 20 20000000000000000000
20 21 210000000000000000000
The terms on the third column can be summed without carry in decimal base.
PROG
(PARI) See Links section.
CROSSREFS
Sequence in context: A368728 A276568 A295020 * A039691 A298639 A276347
KEYWORD
nonn,base
AUTHOR
Rémy Sigrist, Jan 17 2018
STATUS
approved