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 A291379 #7 Sep 04 2017 19:30:22 %S A291379 0,0,0,1,4,6,4,2,8,28,56,71,68,94,228,497,808,1044,1352,2316,4608, %T A291379 8264,12592,17717,26968,47044,83912,138417,211052,319850,517356, %U A291379 881918,1483336,2377252,3700648,5853067,9605596,15991378,26154700,41734433,66214096 %N A291379 p-INVERT of (1,1,0,0,0,0,...), where p(S) = 1 - S^4. %C A291379 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 A291379 See A291382 for a guide to related sequences. %H A291379 Clark Kimberling, <a href="/A291379/b291379.txt">Table of n, a(n) for n = 0..1000</a> %H A291379 <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (0, 0, 0, 1, 4, 6, 4, 1) %F A291379 G.f.: -((x^3 (1 + x)^4)/((-1 + x + x^2) (1 + x + x^2) (1 + x^2 + 2 x^3 + x^4))). %F A291379 a(n) = a(n-4) + 4*a(n-5) + 6*a(n-6) + 4*a(n-7) + a(n-8) for n >= 9. %t A291379 z = 60; s = x + x^2; p = (1 - s)^4; %t A291379 Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A019590 *) %t A291379 Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1] (* A291379 *) %Y A291379 Cf. A019590, A291382. %K A291379 nonn,easy %O A291379 0,5 %A A291379 _Clark Kimberling_, Sep 04 2017