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 A133569 A133566 * A007318 as infinite lower triangular matrices. 1
 1, 1, 1, 2, 3, 1, 1, 3, 3, 1, 2, 7, 9, 5, 1, 1, 5, 10, 10, 5, 1, 2, 11, 25, 30, 20, 7, 1, 1, 7, 21, 35, 35, 21, 7, 1, 2, 15, 49, 91, 105, 77, 35, 9, 1, 1, 9, 36, 84, 126, 126, 84, 36, 9, 1 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 COMMENTS Row sums = A122756: (1, 2, 6, 8, 24, 32, 96, ...). With offset (0,4); triangle T(n,k), 0 <= k <= n, given by [1,1,-3,1,0,0,0,0,0,0,0,...] DELTA [1,0,-2,1,0,0,0,0,0,0,0,...] where DELTA is the operator defined in A084938. - Philippe Deléham, Dec 15 2007 LINKS FORMULA T(n,k) = T(n-2,k) + 2*T(n-2,k-1) + T(n-2,k-2), T(0,0) = 1, T(1,0) = T(1,1) = 1, T(2,0) = 2, T(2,1) = 3, T(2,2) = 1, T(n,k) = 0 if k < 0 or if k > n. - Philippe Deléham, Sep 17 2014 G.f.: (-1-x-x*y-x^2-x^2*y)/((x*y+1+x)*(-1+x+x*y)). - R. J. Mathar, Aug 12 2015 EXAMPLE First few rows of the triangle:   1;   1,  1;   2,  3,  1;   1,  3,  3,  1;   2,  7,  9,  5,  1;   1,  5, 10, 10,  5,  1;   2, 11, 25, 30, 20,  7,  1;   1,  7, 21, 35, 35, 21,  7,  1;   ... CROSSREFS Cf. A133566, A122756. Sequence in context: A282290 A178795 A123185 * A141071 A004648 A265848 Adjacent sequences:  A133566 A133567 A133568 * A133570 A133571 A133572 KEYWORD nonn,tabl AUTHOR Gary W. Adamson, Sep 16 2007 STATUS approved

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Last modified September 21 16:31 EDT 2021. Contains 347598 sequences. (Running on oeis4.)