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 A094039 #13 Feb 06 2022 06:20:23 %S A094039 0,1,2,6,16,46,132,386,1136,3366,10012,29866,89256,267086,799892, %T A094039 2396946,7185376,21545206,64613772,193797626,581305496,1743741726, %U A094039 5230875652,15691927906,47074385616,141220360646,423655489532 %N A094039 Binomial transform of (Jacobsthal(n) + 2^n*Jacobsthal(-n))/2. %C A094039 Binomial transform of Jacobsthal(n)(1-(-1)^n)/2. %C A094039 Starting with "1" = A001045 convolved with A025192: i.e., (1, 2, 6, 16, 46, ...) = (1, 1, 3, 5, 11, ...) * (1, 2, 6, 18, 54, ...). - _Gary W. Adamson_, May 10 2013 %H A094039 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (4,-1,-6). %F A094039 G.f.: x(1-2x-x^2)/((1+x)(1-2x)(1-3x)) %F A094039 a(n) = 3^n/6 - (-1)^n/6 + 2^n/6 - 0^n/6. %Y A094039 Cf. A001045, A094038, A051450. %Y A094039 Cf. A025192. %K A094039 easy,nonn %O A094039 0,3 %A A094039 _Paul Barry_, Apr 23 2004