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A295908
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Triangle in which n-th row lists divisors d of n such that n/d is squarefree.
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0
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1, 1, 2, 1, 3, 2, 4, 1, 5, 1, 2, 3, 6, 1, 7, 4, 8, 3, 9, 1, 2, 5, 10, 1, 11, 2, 4, 6, 12, 1, 13, 1, 2, 7, 14, 1, 3, 5, 15, 8, 16, 1, 17, 3, 6, 9, 18, 1, 19, 2, 4, 10, 20, 1, 3, 7, 21, 1, 2, 11, 22, 1, 23, 4, 8, 12, 24, 5, 25, 1, 2, 13, 26, 9, 27, 2, 4, 14, 28
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OFFSET
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1,3
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COMMENTS
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For any n > 0:
- the n-th row has A034444(n) terms,
- the n-th row has leading term A003557(n).
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LINKS
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FORMULA
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EXAMPLE
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Triangle begins:
1: [1]
2: [1, 2]
3: [1, 3]
4: [2, 4]
5: [1, 5]
6: [1, 2, 3, 6]
7: [1, 7]
8: [4, 8]
9: [3, 9]
10: [1, 2, 5, 10]
11: [1, 11]
12: [2, 4, 6, 12]
13: [1, 13]
14: [1, 2, 7, 14]
15: [1, 3, 5, 15]
16: [8, 16]
17: [1, 17]
18: [3, 6, 9, 18]
19: [1, 19]
20: [2, 4, 10, 20]
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PROG
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(PARI) for (n=1, 28, fordiv (n, d, if (issquarefree(n/d), print1 (d ", "))))
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CROSSREFS
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KEYWORD
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nonn,tabf
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AUTHOR
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STATUS
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approved
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