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A325785
Reading the first column of this array or its successive antidiagonals is the same as reading this sequence.
4
1, 2, 2, 3, 4, 2, 5, 6, 7, 3, 8, 9, 10, 11, 4, 12, 13, 14, 15, 16, 2, 17, 18, 19, 20, 21, 22, 5, 23, 24, 25, 26, 27, 28, 29, 6, 30, 31, 32, 33, 34, 35, 36, 37, 7, 38, 39, 40, 41, 42, 43, 44, 45, 46, 3, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 8, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 9, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 10
OFFSET
1,2
COMMENTS
The array is always extended by its antidiagonals with the smallest term not yet present that doesn't lead to a contradiction. The sequence is thus the lexicographically earliest of its kind.
FORMULA
a(n*(n+1)/2) = a(n). - Rémy Sigrist, May 21 2019
EXAMPLE
Array:
1 2 3 5 8 12 17 23 30 38 47 ...
2 4 6 9 13 18 24 31 39 48 58 ...
2 7 10 14 19 25 32 40 49 59 70 ...
3 11 15 20 26 33 41 50 60 71 83 ...
4 16 21 27 34 42 51 61 72 84 97 ...
2 22 28 35 43 52 62 73 85 98 112 ...
5 29 36 44 53 63 74 86 99 113 128 ...
6 37 45 54 64 75 87 100 114 129 145 ...
7 46 55 65 76 88 101 115 130 146 163 ...
3 56 66 77 89 102 116 131 147 164 182 ...
8 67 78 90 103 117 132 148 165 183 202 ...
...
CROSSREFS
Cf. A325783 and A325784 where the same idea is developed.
Cf. A000217.
Sequence in context: A363100 A367467 A333937 * A207632 A175503 A333389
KEYWORD
tabl,nonn
AUTHOR
Eric Angelini, May 21 2019
STATUS
approved