A291890 Number of symmetrically unique Dyck paths of semilength n and height six.

1, 6, 41, 209, 1005, 4411, 18546, 74854, 294293, 1131635, 4280686, 15974526, 58974616, 215772740, 783598381, 2827768273, 10149744903, 36261522803, 129027358151, 457486923079, 1617031493924, 5699720240694, 20040736126691, 70308818376855, 246171461366950

Offset

6,2

Links

Alois P. Heinz, Table of n, a(n) for n = 6..1000

Index entries for linear recurrences with constant coefficients, signature (12, -51, 66, 144, -540, 411, 510, -1006, 380, 282, -284, 84, -8).

Formula

G.f.: x^6*(20*x^2-43*x^3+48*x^4-20*x^5+x^7-6*x+1) / ((2*x-1) *(2*x^2-4*x+1) *(x^3-2*x^2-x+1) *(x^3-6*x^2+5*x-1) *(2*x^4-4*x^2+1)).

Crossrefs

Column k=6 of A291883.

Sequence in context: A257602 A135232 A371536 * A217326 A196433 A197196

Adjacent sequences: A291887 A291888 A291889 * A291891 A291892 A291893

Keyword

nonn,easy

Author

Alois P. Heinz, Sep 05 2017

Status

approved