# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a289788 Showing 1-1 of 1 %I A289788 #17 Aug 11 2017 18:52:45 %S A289788 1,6,31,156,785,3954,19919,100344,505489,2546430,12827791,64620756, %T A289788 325530881,1639881066,8260997855,41615265264,209639359969, %U A289788 1056070674294,5320018479679,26799907726860,135006120168881,680101314855906,3426050596003631,17258932500172776 %N A289788 a(n) = (1/2)*A289787(n). %H A289788 Clark Kimberling, Table of n, a(n) for n = 0..1000 %H A289788 Index entries for linear recurrences with constant coefficients, signature (6, -6, 6, -1) %F A289788 G.f.: (1 + x^2)/(1 - 6 x + 6 x^2 - 6 x^3 + x^4). %F A289788 a(n) = 6*a(n-1) - 6*a(n-2) + 6*a(n-3) - a(n-4). %t A289788 z = 60; s = 2*x/(1 - x)^2; p = 1 - s - s^2; %t A289788 Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A005843 *) %t A289788 u = Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1] (* A289787 *) %t A289788 u/2 (* A289788 *) %Y A289788 Cf. A289780, A289787. %K A289788 nonn,easy %O A289788 0,2 %A A289788 _Clark Kimberling_, Aug 10 2017 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE