A025184 a(n) = T(2n,n), where T is the array defined in A025177.

1, 1, 7, 35, 189, 1038, 5797, 32747, 186615, 1070762, 6177698, 35802935, 208279007, 1215507450, 7113090285, 41724381765, 245258504925, 1444292029818, 8519114704870, 50323176446818, 297654524450998

Offset

0,3

Links

Table of n, a(n) for n=0..20.

Formula

a(n) = (2*(3*n+2)*(3*n+1)*A006605(n)-(19*n+4)*(2*n-1)*A006605(n-1))/(13*n+4) for n>0. [Mark van Hoeij, Jul 02 2010]

Conjecture: 33*n*(3*n-1)*(3*n-2)*a(n) +11*(2047*n^3-10725*n^2+17192*n-8520)*a(n-1) +9*(-4397*n^3-10169*n^2+110500*n-145368)*a(n-2) -54*(2*n-5)*(5353*n^2-33313*n+53904)*a(n-3) -115668*(2*n-5)*(2*n-7)*(n-4)*a(n-4)=0. - R. J. Mathar, Feb 25 2015

Maple

A025184 := proc(n)
        A025177(2*n, n) ;
end proc: # R. J. Mathar, Jul 28 2016

Crossrefs

Sequence in context: A295647 A026128 A026157 * A360083 A267712 A377158

Adjacent sequences: A025181 A025182 A025183 * A025185 A025186 A025187

Keyword

nonn

Author

Clark Kimberling

Status

approved