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 A106823 Triangle read by rows: g.f. for row n is Product( (x^i-x^(r+1))/(1-x^i), i = 1..r-2). 1
 1, 1, 1, 0, 1, 1, 1, 1, 0, 0, 0, 1, 1, 2, 2, 2, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 2, 3, 3, 3, 3, 2, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 3, 4, 4, 5, 4, 4, 3, 2, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 3, 4, 5, 6, 6, 6, 6, 5, 4, 3, 2, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,14 REFERENCES See A008968 for references. LINKS EXAMPLE Initial rows are: [1] [1] [1] [0, 1, 1, 1, 1] [0, 0, 0, 1, 1, 2, 2, 2, 1, 1] [0, 0, 0, 0, 0, 0, 1, 1, 2, 3, 3, 3, 3, 2, 1, 1] [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 3, 4, 4, 5, 4, 4, 3, 2, 1, 1] MAPLE f3:=r->mul( (x^i-x^(r+1))/(1-x^i), i = 1..r-3); for r from 1 to 10 do series(f3(r), x, 50); od: CROSSREFS If the initial zeros in each row are omitted, we get A008968. Cf. A008967, A008968, A106822. Sequence in context: A112159 A058101 A132980 * A160096 A029446 A288160 Adjacent sequences:  A106820 A106821 A106822 * A106824 A106825 A106826 KEYWORD nonn,tabf AUTHOR N. J. A. Sloane, May 20 2005 STATUS approved

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Last modified July 23 13:58 EDT 2019. Contains 325254 sequences. (Running on oeis4.)