A025189 a(n) = T(n,[ n/2 ]), where T is the array defined in A025177.

1, 1, 1, 2, 7, 11, 35, 56, 189, 302, 1038, 1662, 5797, 9295, 32747, 52572, 186615, 299898, 1070762, 1722236, 6177698, 9943555, 35802935, 57663784, 208279007, 335631410, 1215507450, 1959644390, 7113090285, 11472439905, 41724381765, 67320086700

Offset

0,4

Links

Table of n, a(n) for n=0..31.

Prog

Contribution from Michael B. Porter, Feb 02 2010: (Start)
(PARI) g=matrix(33, 65);
for(n=0, 32, for(k=0, 2*n, g[n+1, k+1]=0));
g[1, 1]=1;
g[2, 1]=1; g[2, 2]=0; g[2, 3]=1;
g[3, 1]=1; g[3, 2]=1; g[3, 3]=2; g[3, 4]=1; g[3, 5]=1;
for(n=0, 2, k=floor(n/2); print(n, " ", k, " ", g[n+1, k+1]))
for(n=3, 32, g[n+1, 1]=1; print(n, " 1 1"); g[n+1, 2]=n-1; print(n, " 2 ", n-1); for(k=2, 2*n, g[n+1, k+1]=g[n, k-1]+g[n, k]+g[n, k+1]; if(k==floor(n/2), print(n, " ", k, " ", g[n+1, k+1])))) (End)

Crossrefs

Sequence in context: A371201 A026133 A026162 * A297348 A023250 A106013

Adjacent sequences: A025186 A025187 A025188 * A025190 A025191 A025192

Keyword

nonn

Author

Clark Kimberling

Status

approved