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 A383324 #14 Apr 25 2025 18:49:29 %S A383324 0,1,2,5,16,49,146,437,1312,3937,11810,35429,106288,318865,956594, %T A383324 2869781,8609344,25828033,77484098,232452293,697356880,2092070641, %U A383324 6276211922,18828635765,56485907296,169457721889,508373165666,1525119496997,4575358490992,13726075472977 %N A383324 a(n) = round(3^n/5). %H A383324 Paolo Xausa, <a href="/A383324/b383324.txt">Table of n, a(n) for n = 0..1000</a> %H A383324 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-1,3). %F A383324 a(n) = floor((3^n+2)/5). %F A383324 a(n) = 3*a(n-1) - a(n-2) + 3*a(n-3) for n > 2. %F A383324 G.f.: x*(x - 1)/((3*x - 1)*(x^2 + 1)). %F A383324 E.g.f.: (exp(5*x) - cos(x) + 2*sin(x))/5. - _Stefano Spezia_, Apr 24 2025 %t A383324 Round[3^Range[0, 30]/5] (* _Paolo Xausa_, Apr 25 2025 *) %o A383324 (Python) %o A383324 def A383324(n): return (3**n+2)//5 %Y A383324 Cf. A178543 (partial sums). %K A383324 nonn,easy %O A383324 0,3 %A A383324 _Chai Wah Wu_, Apr 23 2025