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 A138382 #11 Aug 31 2025 18:49:31
%S A138382 1,-3,-1,-2,-4,12,4,8,16,-48,-16,-32,-64,192,64,128,256,-768,-256,
%T A138382 -512,-1024,3072,1024,2048,4096,-12288,-4096,-8192,-16384,49152,16384,
%U A138382 32768,65536,-196608,-65536,-131072,-262144,786432,262144,524288,1048576,-3145728
%N A138382 First differences of A138380. Second differences of A138377.
%H A138382 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,-4).
%F A138382 a(n) = -4*a(n-4).
%t A138382 Differences[LinearRecurrence[{0,0,0,-4},{0,1,3,2},60],2] (* _Harvey P. Dale_, Mar 19 2012 *)
%t A138382 LinearRecurrence[{0, 0, 0, -4},{1, -3, -1, -2},42] (* _Ray Chandler_, Aug 03 2015 *)
%Y A138382 Cf. A138380, A138377.
%K A138382 sign,easy,changed
%O A138382 0,2
%A A138382 _Paul Curtz_, May 08 2008
%E A138382 Definition corrected by _R. J. Mathar_, May 09 2008
%E A138382 More terms from _Harvey P. Dale_, Mar 19 2012