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 A158926 #5 Jul 03 2023 11:13:32 %S A158926 0,0,0,-9,27,-54,99,-189,378,-765,1539,-3078,6147,-12285,24570,-49149, %T A158926 98307,-196614,393219,-786429,1572858,-3145725,6291459,-12582918, %U A158926 25165827,-50331645,100663290,-201326589,402653187,-805306374,1610612739,-3221225469,6442450938 %N A158926 First differences of A158916. %H A158926 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (-3, -3, -2). %F A158926 a(n) = -3a(n-1)-3a(n-2)-2a(n-3), n > 3. %F A158926 a(n) = 9*(-1)^n*A024495(n+1) . %F A158926 G.f.: -9*x^3/((2*x+1)*(1+x+x^2)). - _R. J. Mathar_, Apr 08 2009 %K A158926 sign,easy %O A158926 0,4 %A A158926 _Paul Curtz_, Mar 31 2009 %E A158926 Edited and extended by _R. J. Mathar_, Apr 08 2009