A202690 The triangle in A185356 with the central column of zeros omitted.

1, 1, 0, 1, 1, 2, 4, 4, 3, 3, 2, 0, 0, 4, 8, 11, 11, 14, 16, 16, 80, 80, 76, 68, 57, 57, 46, 32, 16, 0, 0, 80, 160, 236, 304, 361, 361, 418, 464, 496, 512, 512, 3904, 3904, 3824, 3664, 3428, 3124, 2763, 2763, 2402, 1984, 1520, 1024, 512, 0

Offset: 1

Author

N. J. A. Sloane, Dec 22 2011

Keywords

• nonn
• tabf

Examples

			Triangle begins:
                     1 1
                 0   1 1   2
             4   4   3 3   2   0
         0   4   8  11 11  14  16  16
    80  80  76  68  57 57  46  32  16  0
  0 80 160 236 304 361 361 418 464 496 512 512
		

Links

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

Crossrefs

Cf. A185356, A202691, A202704.

Programs

PARI

T(n,k) = {if ((k==0), return(0)); if (n==1, if (abs(k)==1, return(1))); 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

Extensions

More terms from Michel Marcus, Jun 03 2020