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 A058257 Triangle read by rows: this is a variant of A008280 in which 2 rows go from left to right, 2 from right to left, 2 from left to right, etc. 5
 1, 0, 1, 0, 0, 1, 1, 1, 1, 0, 3, 2, 1, 0, 0, 0, 3, 5, 6, 6, 6, 0, 0, 3, 8, 14, 20, 26, 71, 71, 71, 68, 60, 46, 26, 0, 413, 342, 271, 200, 132, 72, 26, 0, 0, 0, 413, 755, 1026, 1226, 1358, 1430, 1456, 1456, 1456, 0, 0, 413, 1168, 2194, 3420, 4778, 6208, 7664, 9120, 10576 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,11 COMMENTS Suggested by first Atkinson reference. REFERENCES M. D. Atkinson: Zigzag permutations and comparisons of adjacent elements, Information Processing Letters 21 (1985), 187-189. M. D. Atkinson: Partial orders and comparison problems, Sixteenth Southeastern Conference on Combinatorics, Graph Theory and Computing, (Boca Raton, Feb 1985), Congressus Numerantium 47, 77-88. LINKS Reinhard Zumkeller, Rows n = 0..120 of triangle, flattened J. Millar, N. J. A. Sloane and N. E. Young, A new operation on sequences: the Boustrophedon on transform, J. Combin. Theory, 17A 44-54 1996 (Abstract, pdf, ps). EXAMPLE 1; 0,1; 0,0,1; 1,1,1,0; 3,2,1,0,0; 0,3,5,6,6,6; ... 1 PROG (Haskell) a058257 n k = a058257_tabl !! n !! k a058257_row n = a058257_tabl !! n a058257_tabl = [1] : ox 0 [1] where    ox turn xs = ys : ox (mod (turn + 1) 4) ys       where ys | turn <= 1 = scanl (+) 0 xs                | otherwise = reverse \$ scanl (+) 0 \$ reverse xs -- Reinhard Zumkeller, Nov 01 2013 CROSSREFS Cf. A058258, A008280, A000111. Sequence in context: A085075 A321518 A267883 * A083199 A274537 A305234 Adjacent sequences:  A058254 A058255 A058256 * A058258 A058259 A058260 KEYWORD nonn,easy,tabl,nice AUTHOR N. J. A. Sloane, Dec 06 2000 EXTENSIONS More terms from Larry Reeves (larryr(AT)acm.org), Dec 12 2000 STATUS approved

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Last modified February 21 16:08 EST 2019. Contains 320375 sequences. (Running on oeis4.)