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

Author

Clark Kimberling

Keywords

• nonn

Programs

Maple

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

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