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A331010
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Lexicographically earliest sequence of distinct positive terms that can be viewed as an irregular table where the n-th row has A000005(a(n)) terms and T(n, k) is a multiple of the k-th divisor of a(n) (=A027750(a(n), k)).
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4
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1, 2, 4, 3, 6, 8, 5, 9, 7, 10, 12, 18, 11, 14, 16, 24, 13, 15, 17, 21, 27, 19, 28, 20, 22, 25, 30, 23, 26, 33, 32, 36, 48, 29, 34, 39, 42, 45, 54, 31, 44, 35, 38, 49, 56, 37, 40, 52, 64, 80, 41, 46, 51, 60, 66, 72, 84, 96, 43, 65, 47, 57, 50, 75, 53, 68, 55
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listen;
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OFFSET
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1,2
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COMMENTS
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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.
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LINKS
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EXAMPLE
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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]
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PROG
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(PARI) See Links section.
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CROSSREFS
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KEYWORD
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AUTHOR
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STATUS
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approved
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