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Search: id:A080786
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| A080786 |
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Triangle T(n,k) = number of k-smooth numbers <= n, read by rows. |
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1
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| 1, 1, 2, 1, 2, 3, 1, 3, 4, 4, 1, 3, 4, 4, 5, 1, 3, 5, 5, 6, 6, 1, 3, 5, 5, 6, 6, 7, 1, 4, 6, 6, 7, 7, 8, 8, 1, 4, 7, 7, 8, 8, 9, 9, 9, 1, 4, 7, 7, 9, 9, 10, 10, 10, 10, 1, 4, 7, 7, 9, 9, 10, 10, 10, 10, 11, 1, 4, 8, 8, 10, 10, 11, 11, 11, 11, 12, 12, 1, 4, 8, 8, 10, 10, 11, 11, 11, 11, 12, 12, 13, 1, 4
(list; table; graph; listen)
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OFFSET
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1,3
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COMMENT
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T(n,n-1)=A014684(n) for n>1;
T(n,2)=A029837(n) for n>1; T(n,3)=A071521(n) for n>2; T(n,5)=A071521(n) for n>4.
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LINKS
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Eric Weisstein's World of Mathematics, Smooth Number.
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EXAMPLE
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Triangle begins:
.................. 1
................ 1...2
.............. 1...2...3
............ 1...3...4...4
.......... 1...3...4...4...5
........ 1...3...5...5...6...6
...... 1...3...5...5...6...6...7
.... 1...4...6...6...7...8...8...8
.. 1...4...7...7...8...8...9...9...9.
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CROSSREFS
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Cf. A000079, A003586, A051037, A002473, A051038, A080197, A080681, A080682, A080683.
Sequence in context: A116908 A072851 A103627 this_sequence A036838 A066010 A109974
Adjacent sequences: A080783 A080784 A080785 this_sequence A080787 A080788 A080789
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KEYWORD
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nonn,tabl
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AUTHOR
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Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Mar 12 2003
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