# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a291255 Showing 1-1 of 1 %I A291255 #5 Sep 03 2017 21:42:22 %S A291255 2,7,18,55,144,404,1060,2853,7442,19573,50670,131368,337622,866819, %T A291255 2213650,5642899,14332988,36335548,91872760,231875713,584030738, %U A291255 1468631153,3686943130,9242753104,23138167146,57851432575,144470316562,360384852207,898051760168 %N A291255 p-INVERT of (0,1,0,1,0,1,...), where p(S) = (1 - S - 2 S^2)^2. %C A291255 Suppose s = (c(0), c(1), c(2), ...) is a sequence and p(S) is a polynomial. Let S(x) = c(0)*x + c(1)*x^2 + c(2)*x^3 + ... and T(x) = (-p(0) + 1/p(S(x)))/x. The p-INVERT of s is the sequence t(s) of coefficients in the Maclaurin series for T(x). Taking p(S) = 1 - S gives the "INVERT" transform of s, so that p-INVERT is a generalization of the "INVERT" transform (e.g., A033453). %C A291255 See A291219 for a guide to related sequences. %H A291255 Clark Kimberling, Table of n, a(n) for n = 0..1000 %H A291255 Index entries for linear recurrences with constant coefficients, signature (2, 7, -10, -16, 10, 7, -2, -1) %F A291255 G.f.: (2 + 3 x - 10 x^2 - 10 x^3 + 10 x^4 + 3 x^5 - 2 x^6)/(1 - x - 4 x^2 + x^3 + x^4)^2. %F A291255 a(n) = 2*a(n-1) + 7*a(n-2) - 10*a(n-3) - 16*a(n-4) + 10*a(n-5) + 7*a(n-6) - 2*a(n-7) - a(n-8) for n >= 9. %t A291255 z = 60; s = x/(1 - x^2); p = (1 - s - 2 s^2)^2; %t A291255 Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000035 *) %t A291255 Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1] (* A291255 *) %Y A291255 Cf. A000035, A291219. %K A291255 nonn,easy %O A291255 0,1 %A A291255 _Clark Kimberling_, Sep 02 2017 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE