A259319 - OEIS

%I #17 Aug 16 2015 12:04:01

%S 2,164,1414,6216,19338,48620,105742,206992,374034,634676,1023638,

%T 1583320,2364570,3427452,4842014,6689056,9060898,12062148,15810470,

%U 20437352,26088874,32926476,41127726,50887088,62416690,75947092,91728054,110029304,131141306,155376028

%N a(n) = 2*A002309(n).

%H Colin Barker, <a href="/A259319/b259319.txt">Table of n, a(n) for n = 1..1000</a>

%H J. L. Bailey, Jr., <a href="http://dx.doi.org/10.1214/aoms/1177732978">A table to facilitate the fitting of certain logistic curves</a>, Annals Math. Stat., 2 (1931), 355-359.

%H J. L. Bailey, <a href="/A002309/a002309.pdf">A table to facilitate the fitting of certain logistic curves</a>, Annals Math. Stat., 2 (1931), 355-359. [Annotated scanned copy]

%H <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (6,-15,20,-15,6,-1).

%F a(n) = (2*n*(7-40*n^2+48*n^4))/15. - _Colin Barker_, Jun 29 2015

%F G.f.: 2*x*(x^4+76*x^3+230*x^2+76*x+1) / (x-1)^6. - _Colin Barker_, Jun 29 2015

%o (PARI) Vec(2*x*(x^4+76*x^3+230*x^2+76*x+1)/(x-1)^6 + O(x^100)) \\ _Colin Barker_, Jun 29 2015

%Y Cf. A002309.

%K nonn,easy

%O 1,1

%A _N. J. A. Sloane_, Jun 24 2015