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 A166454 Triangle read by rows, (1/2)*(Pascal's triangle - Sierpinski's gasket); (1/2)*(A007318 - A047999). 5
 1, 1, 1, 2, 3, 2, 2, 5, 5, 2, 3, 7, 10, 7, 3, 3, 10, 17, 17, 10, 3, 4, 14, 28, 35, 28, 14, 4, 4, 18, 42, 63, 63, 42, 18, 4, 5, 22, 60, 105, 126, 105, 60, 22, 5, 5, 27, 82, 165, 231, 231, 165, 82, 27, 5 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 2,4 COMMENTS Row sums = A120739: (1, 2, 7, 14, 30, 60, 127, 254,...). LINKS Reinhard Zumkeller, Rows n = 2..125 of triangle, flattened FORMULA (1/2)*(A007318 - A047999), nonzero terms. t(n,m) = Floor[Binomial[n, m]/2] [From Roger L. Bagula, Mar 07 2010] EXAMPLE First few rows of the triangle = 1; 1, 1; 2, 3, 2; 2, 5, 5, 2; 3, 7, 10, 7, 3; 3, 10, 17, 17, 10, 3; 4, 14, 28, 35, 28, 14, 4; 4, 18, 42, 63, 63, 42, 18, 4; 5, 22, 60, 105, 126, 105, 60, 22, 5; 5, 27, 82, 165, 231, 231, 165, 82, 27, 5; 6, 33, 110, 247, 396, 462, 396, 247, 110, 33, 6; ... MATHEMATICA Contribution from Roger L. Bagula, Mar 07 2010: (Start) Clear[t, n, m]; t[n_, m_] = Floor[Binomial[n, m]/2]; Table[Table[t[n, m], {m, 1, n - 1}], {n, 2, 12}]; Flatten[%] (End) PROG (Haskell)  Following Bagula's formula a166454 n k = a166454_tabl !! (n-2) !! (k-1) a166454_row n = a166454_tabl !! (n-2) a166454_tabl = map (map (flip div 2) . init . tail) \$ drop 2 a007318_tabl -- Reinhard Zumkeller, Mar 04 2015 CROSSREFS Cf. A007318, A011848, A001700 (central terms). Sequence in context: A027746 A240230 A238689 * A283239 A318177 A128651 Adjacent sequences:  A166451 A166452 A166453 * A166455 A166456 A166457 KEYWORD nonn,tabl AUTHOR Gary W. Adamson, Oct 14 2009 STATUS approved

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Last modified December 10 17:41 EST 2018. Contains 318049 sequences. (Running on oeis4.)