OFFSET
1,2
COMMENTS
This sequence is a permutation of the natural numbers as each row starts with the least value not yet in the sequence.
The prime numbers appear in ascending order.
LINKS
EXAMPLE
The first terms and rows are:
n a(n) row(n)
-- ---- -------------------------
1 1 [1]
2 2 [2, 4]
3 4 [3, 6, 8]
4 3 [5, 9]
5 6 [7, 10, 12, 18]
6 8 [11, 14, 16, 24]
7 5 [13, 15]
8 9 [17, 21, 27]
9 7 [19, 28]
10 10 [20, 22, 25, 30]
11 12 [23, 26, 33, 32, 36, 48]
12 18 [29, 34, 39, 42, 45, 54]
13 11 [31, 44]
14 14 [35, 38, 49, 56]
15 16 [37, 40, 52, 64, 80]
16 24 [41, 46, 51, 60, 66, 72, 84, 96]
PROG
(PARI) See Links section.
CROSSREFS
KEYWORD
AUTHOR
Rémy Sigrist, Jan 06 2020
STATUS
approved