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A202704 Constructed by the same rule as A185356 and A202690, but with first row 0, 1. 4
0, 1, 0, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 2, 3, 3, 4, 5, 5, 23, 23, 22, 20, 17, 17, 14, 10, 5, 0, 0, 23, 46, 68, 88, 105, 105, 122, 136, 146, 151, 151, 1141, 1141, 1118, 1072, 1004, 916, 811, 811, 706, 584, 448, 302, 151, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,15

COMMENTS

Equals A202690 - A202691.

LINKS

Table of n, a(n) for n=1..56.

M. Josuat-Verg├Ęs, J.-C. Novelli and J.-Y. Thibon, The algebraic combinatorics of snakes, arXiv preprint arXiv:1110.5272 [math.CO], 2011.

EXAMPLE

Triangle begins

                   0 1

               0   0 0   1

            1  1   1 1   1   0

         0  1  2   3 3   4   5   5

     23 23 22 20  17 17  14  10  5   0

   0 23 46 68 88 105 105 122 136 146 151 151

PROG

(PARI) T(n, k) = {if ((k==0), return(0)); if (n==1, if (abs(k)==1, if (k>0, return(1), return (0)))); if (n%2, if (k<0, sum(j=k+1, n-1, T(n-1, j)), sum(j=k, n-1, T(n-1, j))), if (k<0, sum(j=-n+1, k, T(n-1, j)), sum(j=-n+1, k-1, T(n-1, j)))); }

tabf(nn) = {for (n=1, nn, for (k=-n, n, if (k, print1(T(n, k), ", ")); ); print; ); } \\ Michel Marcus, Jun 03 2020

CROSSREFS

Cf. A007836, A185356, A202690, A202691.

Sequence in context: A290736 A007998 A203899 * A273004 A029931 A350311

Adjacent sequences:  A202701 A202702 A202703 * A202705 A202706 A202707

KEYWORD

nonn,tabf

AUTHOR

N. J. A. Sloane, Dec 23 2011

EXTENSIONS

More terms from Michel Marcus, Jun 03 2020

STATUS

approved

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Last modified May 20 01:04 EDT 2022. Contains 353847 sequences. (Running on oeis4.)