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A306993 Lexicographically earliest sequence of distinct positive terms such that for any n > 0, n * a(n) is digitally balanced. 3
2, 1, 3, 11, 7, 25, 5, 23, 15, 17, 4, 13, 12, 43, 9, 47, 10, 31, 29, 37, 34, 26, 8, 39, 6, 22, 30, 81, 19, 27, 18, 95, 63, 21, 61, 67, 20, 57, 24, 70, 56, 51, 14, 55, 49, 54, 16, 53, 45, 58, 42, 65, 48, 46, 44, 41, 38, 50, 62, 149, 35, 59, 33, 191, 52, 127, 36 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Digitally balanced numbers correspond to A031443.
This sequence has similarities with A300868.
This sequence is a self-inverse permutation of the natural numbers.
LINKS
Rémy Sigrist, Colored scatterplot of the first 10000 terms (where the color is function of A000120(n*a(n)))
EXAMPLE
The first terms, alongside the binary representation of n * a(n), are:
n a(n) bin(n * a(n))
-- ---- --------------
1 2 10
2 1 10
3 3 1001
4 11 101100
5 7 100011
6 25 10010110
7 5 100011
8 23 10111000
9 15 10000111
10 17 10101010
11 4 101100
12 13 10011100
13 12 10011100
14 43 1001011010
15 9 10000111
16 47 1011110000
PROG
(PARI) See Links section.
CROSSREFS
Sequence in context: A372523 A196371 A276116 * A119928 A215265 A036448
KEYWORD
nonn,look,base
AUTHOR
Rémy Sigrist, Mar 18 2019
STATUS
approved

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Last modified May 27 02:27 EDT 2024. Contains 372847 sequences. (Running on oeis4.)