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 A084177 #11 Sep 08 2022 08:45:11 %S A084177 0,1,5,27,137,691,3465,17347,86777,433971,2170025,10850467,54253017, %T A084177 271266451,1356334985,6781680387,33908412857,169542086131, %U A084177 847710474345,4238552459107,21192762470297,105963812701011,529819064204105 %N A084177 Binomial transform of Jacobsthal oblongs. %C A084177 Binomial transform of A084175. %H A084177 Vincenzo Librandi, <a href="/A084177/b084177.txt">Table of n, a(n) for n = 0..500</a> %H A084177 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (6,-3,-10). %F A084177 a(n) = (2*5^n - (-1)^n - 2^n)/9. %F A084177 G.f.: x*(1-x)/((1+x)*(1-2*x)*(1-5*x)). %F A084177 a(n) = 6*a(n-1) - 3*a(n-2) - 10*a(n-3). %F A084177 E.g.f.: (2*exp(5*x) - exp(2*x) - exp(-x))/9. %o A084177 (Magma) [(2*5^n-(-1)^n-2^n)/9: n in [0..35]]; // _Vincenzo Librandi_, Jul 05 2011 %Y A084177 Cf. A001045. %K A084177 easy,nonn %O A084177 0,3 %A A084177 _Paul Barry_, May 18 2003