This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A291729 #4 Sep 11 2017 20:04:29 %S A291729 2,5,14,39,106,290,794,2173,5946,16272,44530,121860,333480,912597, %T A291729 2497400,6834349,18702782,51181767,140063294,383295214,1048920220, %U A291729 2870460125,7855260268,21496593296,58827270844,160985870984,440551640160,1205607339709,3299247863502 %N A291729 p-INVERT of (1,0,1,0,0,0,0,...), where p(S) = 1 - 2 S - S^2. %C A291729 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 A291729 See A291728 for a guide to related sequences. %H A291729 Clark Kimberling, <a href="/A291729/b291729.txt">Table of n, a(n) for n = 0..1000</a> %H A291729 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (2, 1, 2, 2, 0, 1) %F A291729 G.f.: (-2 - x - 2 x^2 - 2 x^3 - x^5)/(-1 + 2 x + x^2 + 2 x^3 + 2 x^4 + x^6). %F A291729 a(n) = 2*a(n-1) + a(n-2) + 2*a(n-3) + 2*a(n-4) + a(n-6) for n >= 7. %t A291729 z = 60; s = x + x^3; p = 1 - 2 s - s^2; %t A291729 Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A154272 *) %t A291729 Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1] (* A291729 *) %Y A291729 Cf. A154272, A291728. %K A291729 nonn,easy %O A291729 0,1 %A A291729 _Clark Kimberling_, Sep 11 2017