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 A143858 Number of pairwise disjoint unions of m integer-to-integer subintervals of [0,n]; a rectangular array by antidiagonals, n>=2m-1, m>=1. 5
 1, 3, 1, 6, 5, 1, 10, 15, 7, 1, 15, 35, 28, 9, 1, 21, 70, 84, 45, 11, 1, 28, 126, 210, 165, 66, 13, 1, 36, 210, 462, 495, 286, 91, 15, 1, 45, 330, 924, 1287, 1001, 455, 120, 17, 1, 55, 495, 1716, 3003, 3003, 1820, 680, 153, 19, 1, 66, 715, 3003, 6435, 8008, 6188, 3060 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Main diagonal: A025174. LINKS Reinhard Zumkeller, Rows n = 1..125 of triangle, flattened FORMULA R(m,n) = C(n+1,2m), where n>=2m-1, m>=1. R is also given by the absolute values of terms in A109954. EXAMPLE R(2,4) counts these unions of 2 subintervals of [0,4]: [0,1]U[2,3], [0,1]U[2,4], [0,1]U[3,4], [0,2]U[3,4], [1,2]U[3,4]. PROG (Haskell)  Seen as a triangle read by rows a143858 n k = a143858_tabl !! (n-1) !! k a143858_row n = a143858_tabl !! (n-1) a143858_tabl = map ((++ [1]) . tail) a258993_tabl -- Reinhard Zumkeller, Jun 22 2015 CROSSREFS Cf. A007318, A025174, A109954, A085478, A258993. Sequence in context: A208331 A061702 A112351 * A258993 A109954 A153641 Adjacent sequences:  A143855 A143856 A143857 * A143859 A143860 A143861 KEYWORD nonn,tabf AUTHOR Clark Kimberling, Sep 03 2008 STATUS approved

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Last modified October 14 03:00 EDT 2019. Contains 327995 sequences. (Running on oeis4.)