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A106242 Same triangle as A106243, but with rows read in boustrophedon manner, i.e., in the order in which they were created. 3
1, 0, 1, 0, 1, 1, 0, 2, 3, 3, 0, 6, 11, 13, 13, 0, 26, 50, 67, 73, 73, 0, 146, 286, 403, 479, 505, 505, 0, 1010, 1994, 2876, 3565, 3997, 4143, 4143, 0, 8286, 16426, 23988, 30429, 35299, 38303, 39313, 39313, 0, 78626, 156242, 229844, 295572, 349989, 390403, 415115, 423401, 423401 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,8

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..10010

MAPLE

T:= proc(n, k) option remember;

      local t;

      if n<1 or k<1 then 0

    elif n=1 and k=1 then 1

    elif n=1 and irem(k, 2)=1 or k=1 and irem(n, 2)=0 then 0

    else t:= 1-2*irem(n+k, 2);

             T(n-t, k+t) + T(n, k-1)+T(n-1, k)

      fi

    end:

seq (`if` (irem(d, 2)=1,

  seq (T(d-k, k), k=1..d-1),

  seq (T(n, d-n), n=1..d-1)), d=2..11);  # Alois P. Heinz, Feb 08 2011

MATHEMATICA

T[n_, k_] := T[n, k] = Module[{t}, Which[n<1 || k<1, 0, n == 1 && k == 1, 1, n == 1 && Mod[k, 2] == 1 || k == 1 && Mod[n, 2] == 0, 0, True, t = 1 - 2*Mod[n+k, 2]; T[n-t, k+t] + T[n, k-1] + T[n-1, k]]]; Table[If[Mod[d, 2] == 1, Table[T[d-k, k], {k, 1, d-1}], Table[T[n, d-n], {n, 1, d-1}]], {d, 2, 11}] // Flatten (* Jean-Fran├žois Alcover, Jan 14 2014, translated from Alois P. Heinz's Maple code *)

CROSSREFS

Right-hand diagonal is A059294. Cf. A106243. Row sums give A106327.

Sequence in context: A104172 A091408 A193382 * A121474 A138003 A329232

Adjacent sequences:  A106239 A106240 A106241 * A106243 A106244 A106245

KEYWORD

nonn,tabl,easy

AUTHOR

N. J. A. Sloane, May 29 2005

EXTENSIONS

More terms from Alois P. Heinz, Feb 08 2011

STATUS

approved

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Last modified June 18 18:13 EDT 2021. Contains 345120 sequences. (Running on oeis4.)