OFFSET
1,2
COMMENTS
This sequence is a permutation of the natural numbers (with inverse A319024):
- this sequence is injective,
- this sequence is surjective: by contradiction:
- let m be the least integer missing from the sequence,
- as a(1) = 1, we have m > 1,
- however the only positive integer belonging to both sequences is 1,
- hence a contradiction, QED.
LINKS
EXAMPLE
n a(n) b(n) t(n)
-- ---- ---- ----
1 1 2 3
2 2 4 4
3 3 5 9
4 4 8 6
5 5 6 7
6 9 10 27
7 8 16 14
8 6 9 10
9 7 11 11
10 10 12 12
11 27 29 81
12 16 32 20
13 14 19 16
14 11 13 13
15 12 17 18
16 29 30 31
17 81 82 243
18 32 64 34
19 20 24 22
20 19 21 21
PROG
(PARI) See Links section.
CROSSREFS
KEYWORD
AUTHOR
Rémy Sigrist, Sep 08 2018
STATUS
approved