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 A159334 #14 Jun 02 2025 01:31:35
%S A159334 2,4,9,23,55,126,291,678,1578,3667,8523,19815,46066,107089,248950,
%T A159334 578740,1345409,3127695,7271007,16903042,39294807,91349342,212361454,
%U A159334 493680487,1147667895,2668004163,6202357186,14418731129,33519483178
%N A159334 Transform of A056594 by the T_{1,1} transformation (see link).
%H A159334 G. C. Greubel, <a href="/A159334/b159334.txt">Table of n, a(n) for n = 0..1000</a>
%H A159334 R. Choulet, <a href="http://www.apmep.asso.fr/IMG/pdf/curtz1.pdf">Curtz-like transformation </a>
%H A159334 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,4,-2,1).
%F A159334 O.g.f.: -(2-2*x+3*x^2+x^4)/((x^2+1)*(x^3-2*x^2+3*x-1)).
%F A159334 for n>=0 a(n+5)=3*a(n+4)-3*a(n+3)+4*a(n+2)-2*a(n+1)+a(n)
%t A159334 Join[{2, 4, 9, 23, 55, 126}, LinearRecurrence[{3, -3, 4, -2, 1}, {291, 678, 1578, 3667, 8523}, 45]] (* _G. C. Greubel_, Jun 25 2018 *)
%o A159334 (PARI) x='x+O('x^50); Vec(-(2-2*x+3*x^2+x^4)/((x^2+1)*(x^3-2*x^2+3*x-1))) \\ _G. C. Greubel_, Jun 25 2018
%o A159334 (Magma) I:=[291, 678, 1578, 3667, 8523]; [2, 4, 9, 23, 55, 126] cat [n le 5 select I[n] else 3*Self(n-1) - 3*Self(n-2) + 4*Self(n-3) -2*Self(n-4) +Self(n-5): n in [1..50]]; // _G. C. Greubel_, Jun 25 2018
%Y A159334 Cf. A159328, A159329, A159330, A159331.
%K A159334 easy,nonn
%O A159334 0,1
%A A159334 _Richard Choulet_, Apr 10 2009