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 A171661 Triangle T(n,k) (n >= 0, 0 <= k <= n) read by rows: T(n,0) = T(n,1) = A000984(n); for n >= 2 and k >= 2, T(n,k) = T(n,k-1) - T(n-1,k-2). 1
 1, 2, 2, 6, 6, 4, 20, 20, 14, 8, 70, 70, 50, 30, 16, 252, 252, 182, 112, 62, 32, 924, 924, 672, 420, 238, 126, 64, 3432, 3432, 2508, 1584, 912, 492, 254, 128, 12870, 12870, 9438, 6006, 3498, 1914, 1002, 510, 256, 48620, 48620, 35750, 22880, 13442, 7436 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Table of n, a(n) for n=0..50. EXAMPLE Triangle starts: 1 2,2 6,6,4 20,20,14,8 70,70,50,30,16 CROSSREFS Cf. A000984, A172021. Sequence in context: A033712 A033730 A033754 * A276418 A173869 A247377 Adjacent sequences: A171658 A171659 A171660 * A171662 A171663 A171664 KEYWORD nonn,tabl AUTHOR Mark Dols, Dec 14 2009 EXTENSIONS Edited by N. J. A. Sloane, Jan 24 2010 More terms from Mark Dols, Jan 24 2010 STATUS approved

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Last modified November 29 17:03 EST 2023. Contains 367445 sequences. (Running on oeis4.)