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 A093833 #7 Jun 13 2015 00:51:20 %S A093833 1,2,8,24,76,232,708,2144,6476,19512,58708,176464,530076,1591592, %T A093833 4777508,14337984,43024876,129096472,387333108,1162086704,3486434876, %U A093833 10459654152,31379661508,94140382624,282423944076,847277424632 %N A093833 3^n-Jacobsthal(n). %C A093833 Binomial transform of A052992. Binomial transform is A093834. Partial sums are A004054. Sums of consecutive pairs yield A053581. %C A093833 Contribution from _Johannes W. Meijer_, Aug 15 2010: (Start) %C A093833 An elephant sequence, see A175654. For the corner squares four A[5] vectors, with decimal values 343, 349, 373 and 469, lead to this sequence. For the central square these vectors lead to the companion sequence A175659. %C A093833 (End) %H A093833 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (4,-1,-6) %F A093833 G.f.: (1-x)^2/((1+x)(1-2x)(1-3x)); a(n)=3^n-2^n/3+(-1)^n/3; a(n)=3^n-A001045(n). %K A093833 easy,nonn %O A093833 0,2 %A A093833 _Paul Barry_, Apr 17 2004