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 A118558 #27 Apr 20 2024 04:36:52 %S A118558 -2,-1,79,2399,50623,923519,15752959,260144639,4228250623,68184176639, %T A118558 1095222947839,17557851463679,281200199450623,4501401006735359, %U A118558 72040003462430719,1152780773560811519,18445618199572250623,295138898083176775679,4722294425687923097599 %N A118558 a(n) = (2^n-1)^4 - 2. %H A118558 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (31,-310,1240,-1984,1024). %F A118558 a(n) = (2^n - 1)^4 - 2. %F A118558 G.f.: (1984*x^4-2120*x^3+510*x^2-61*x+2) / ((x-1)*(2*x-1)*(4*x-1)*(8*x-1)*(16*x-1)). - _Colin Barker_, Apr 30 2013 %e A118558 a(0) = (2^0 - 1)^4 - 2 = 0^4 - 2 = -2. %e A118558 a(1) = (2^1 - 1)^4 - 2 = 1^4 - 2 = -1. %e A118558 a(2) = (2^2 - 1)^4 - 2 = 3^4 - 2 = 79. %t A118558 (2^Range[0, 20] - 1)^4 - 2 (* _Paolo Xausa_, Apr 19 2024 *) %o A118558 (PARI) a(n)=(2^n-1)^4-2 \\ _Charles R Greathouse IV_, Feb 19 2016 %Y A118558 Cf. A091516, A091515, A098878, A091514. %Y A118558 Cf. A093112, A098878. %K A118558 easy,sign %O A118558 0,1 %A A118558 _Jonathan Vos Post_, May 03 2006 %E A118558 Offset changed to 0 by _Paolo Xausa_, Apr 19 2024