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A059220 The array in A059219 read by antidiagonals in 'up' direction. 8
1, 0, 1, 2, 1, 0, 0, 2, 3, 5, 15, 12, 8, 5, 0, 0, 15, 27, 39, 48, 55, 239, 221, 190, 152, 103, 55, 0, 0, 239, 460, 680, 871, 1025, 1137, 1199, 6810, 6553, 6062, 5374, 4493, 3471, 2336, 1199, 0, 0, 6810, 13363, 19903, 25958, 31351, 35884, 39399, 41847 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,4

LINKS

G. C. Greubel, Table of n, a(n) for the first 50 rows, flattened

Index entries for sequences related to boustrophedon transform

EXAMPLE

The array begins

   1   1   0   5   0  55   0 ...

   0   1   3   5  48  55   ...

   2   2   8  39 103  ...

   0  12  27 152 ...

  15  15 190 ...

   0 221 ...

MAPLE

See A059219 for Maple code.

MATHEMATICA

max = 9; t[0, 0] = 1; t[0, _?EvenQ] = 0; t[_?OddQ, 0] = 0; t[n_, k_] /; OddQ[n + k] (* up *) := t[n, k] = t[n+1, k-1] + Sum[t[n, j], {j, 0, k-1}]; t[n_, k_] /; EvenQ[n + k] (* down *) := t[n, k] = t[n-1, k+1] + Sum[t[j, k], {j, 0, n-1}]; Table[t[n - k, k], {n, 0, max}, {k, 0, n}] // Flatten (* Jean-Fran├žois Alcover, Aug 19 2013 *)

CROSSREFS

Cf. A000667, A059216, A059219, A059217, A059235.

Sequence in context: A261118 A063181 A247310 * A261630 A301503 A059431

Adjacent sequences:  A059217 A059218 A059219 * A059221 A059222 A059223

KEYWORD

easy,nonn,tabl,nice

AUTHOR

N. J. A. Sloane, Jan 18 2001

EXTENSIONS

More terms from Floor van Lamoen, Jan 19 2001

STATUS

approved

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Last modified September 16 05:49 EDT 2021. Contains 347469 sequences. (Running on oeis4.)