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A336193
Lexicographically earliest sequence of distinct positive integers such that for any n > 0, n + a(n) can be computed without carry in base 10.
1
1, 2, 3, 4, 10, 11, 12, 20, 30, 5, 6, 7, 13, 14, 21, 22, 31, 40, 50, 8, 15, 16, 23, 24, 32, 33, 41, 51, 60, 9, 17, 25, 26, 34, 42, 43, 52, 61, 100, 18, 27, 35, 36, 44, 53, 101, 102, 110, 120, 19, 28, 37, 45, 103, 104, 111, 112, 121, 130, 29, 38, 105, 106, 113
OFFSET
1,2
COMMENTS
This sequence is a decimal variant of A238757.
This sequence is a self-inverse permutation of the natural numbers.
FORMULA
A007953(n + a(n)) = A007953(n) + A007953(a(n)).
EXAMPLE
The first terms, alongside n + a(n), are:
n a(n) n+a(n)
-- ---- ------
1 1 2
2 2 4
3 3 6
4 4 8
5 10 15
6 11 17
7 12 19
8 20 28
9 30 39
10 5 15
11 6 17
12 7 19
13 13 26
14 14 28
15 21 36
PROG
(PARI) s=0; for (n=1, 64, for (v=1, oo, if (!bittest(s, v) && sumdigits(n+v)==sumdigits(n)+sumdigits(v), print1(v", "); s+=2^v; break)))
CROSSREFS
KEYWORD
nonn,base,look
AUTHOR
Rémy Sigrist, Jul 11 2020
STATUS
approved