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 A028262 Elements in 3-Pascal triangle (by row). 22
 1, 1, 1, 1, 3, 1, 1, 4, 4, 1, 1, 5, 8, 5, 1, 1, 6, 13, 13, 6, 1, 1, 7, 19, 26, 19, 7, 1, 1, 8, 26, 45, 45, 26, 8, 1, 1, 9, 34, 71, 90, 71, 34, 9, 1, 1, 10, 43, 105, 161, 161, 105, 43, 10, 1, 1, 11, 53, 148, 266, 322, 266, 148, 53, 11, 1, 1, 12, 64, 201, 414, 588, 588, 414, 201, 64 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,5 COMMENTS T(n+2,k+1) = A007318(n,k) - A007318(n+2,k+1); 0 < k < n. - Reinhard Zumkeller, Aug 02 2012 LINKS Reinhard Zumkeller, >Rows n = 0..150 of triangle, flattened László Németh, Tetrahedron trinomial coefficient transform, Integers (2019) Vol. 19, Article A41. FORMULA After the 3rd row, use Pascal's rule. T(n, k) = C(n, k) + C(n-2, k-1). G.f.: (1+x^2y) / [1-x(1+y)]. - Ralf Stephan, Jan 31 2005 EXAMPLE 1; 1 1; 1 3 1; 1 4 4 1; 1 5 8 5 1; ... MATHEMATICA T[n_, k_] := If[n == 1, 1, Binomial[n, k] + Binomial[n-2, k-1]]; Table[T[n, k], {n, 0, 11}, {k, 0, n}] // Flatten (* Jean-François Alcover, Jan 28 2015 *) PROG (Haskell) a028262 n k = a028262_tabl !! n !! k a028262_row n = a028262_tabl !! n a028262_tabl = [1] : [1, 1] : iterate    (\row -> zipWith (+) ([0] ++ row) (row ++ [0])) [1, 3, 1] -- Reinhard Zumkeller, Aug 02 2012 CROSSREFS Cf. A072405, A028275. Sequence in context: A077228 A049687 A132735 * A173117 A050177 A013580 Adjacent sequences:  A028259 A028260 A028261 * A028263 A028264 A028265 KEYWORD nonn,nice,tabl AUTHOR EXTENSIONS More terms from James A. Sellers STATUS approved

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Last modified October 13 20:38 EDT 2019. Contains 327981 sequences. (Running on oeis4.)