A202704 Constructed by the same rule as A185356 and A202690, but with first row 0, 1.

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

Offset

1,15

Comments

Equals A202690 - A202691.

Links

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

M. Josuat-Vergès, 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