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Search: id:A003988
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| A003988 |
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Triangle with subscripts (1,1),(2,1),(1,2),(3,1),(2,2),(1,3), etc. in which entry (i,j) is [ i/j ]. |
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+0
4
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| 1, 2, 0, 3, 1, 0, 4, 1, 0, 0, 5, 2, 1, 0, 0, 6, 2, 1, 0, 0, 0, 7, 3, 1, 1, 0, 0, 0, 8, 3, 2, 1, 0, 0, 0, 0, 9, 4, 2, 1, 1, 0, 0, 0, 0, 10, 4, 2, 1, 1, 0, 0, 0, 0, 0, 11, 5, 3, 2, 1, 1, 0, 0, 0, 0, 0, 12, 5, 3, 2, 1, 1, 0, 0, 0, 0, 0, 0, 13, 6, 3, 2, 1, 1, 1, 0, 0, 0, 0, 0, 0, 14, 6, 4, 2, 2, 1, 1, 0, 0, 0, 0
(list; table; graph; listen)
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OFFSET
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1,2
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COMMENT
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Another version of A010766.
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FORMULA
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T(n,k) = sum_{i=1}^k A077049(n,i). G.f. sum_{k>0} x^k y^k/(1-x^k) / (1-x) = sum_{k>0} x^k y / (1 - x^k y) / (1-x) = sum_{k>0} x^k sum_{d|k} y^d / (1-x) = A(x,y)/(1-x) where A(x,y) is the g.f. of A077049. - Frank Adams-Watters (FrankTAW(AT)Netscape.net), Jan 28 2006
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CROSSREFS
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Cf. A003056, A049581, A003991, A004247.
Row sums are in A006218. Antidiagonal sums are in A002541.
Sequence in context: A070679 A127374 A098862 this_sequence A144257 A074650 A144955
Adjacent sequences: A003985 A003986 A003987 this_sequence A003989 A003990 A003991
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KEYWORD
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tabl,nonn,easy,nice
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AUTHOR
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Marc LeBrun (mlb(AT)well.com)
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EXTENSIONS
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More terms from James A. Sellers (sellersj(AT)math.psu.edu)
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