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 A257272 #27 Sep 08 2022 08:46:12
%S A257272 4,9,22,60,184,624,2272,8640,33664,132864,527872,2104320,8402944,
%T A257272 33583104,134275072,536985600,2147713024,8590393344,34360655872,
%U A257272 137440788480,549759483904,2199030595584,8796107702272,35184401448960,140737547075584,562950070861824,2251800048566272,9007199724503040
%N A257272 a(n) = 2^(n-1)*(2^n+7).
%C A257272 For n in A057195, a(n) is of deficiency 8, i.e., in A125247.
%C A257272 Also, the third column (k=2) of the table given in A181444.
%H A257272 Colin Barker, <a href="/A257272/b257272.txt">Table of n, a(n) for n = 0..1000</a>
%H A257272 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (6,-8).
%F A257272 a(n) = 2^(n-1)*A168415(n).
%F A257272 n in A057195 <=> A168415(n) in A104066 <=> a(n) in A125247.
%F A257272 G.f.: (4-15*x)/((1-4*x)*(1-2*x)). - _Vincenzo Librandi_, Apr 27 2015
%t A257272 Table[2^(n - 1) (2^n + 7), {n, 0, 30}] (* _Bruno Berselli_, Apr 27 2015 *)
%t A257272 CoefficientList[Series[(4 - 15 x)/((1 - 4 x) (1 - 2 x)), {x, 0, 30}], x] (* _Vincenzo Librandi_, Apr 27 2015 *)
%o A257272 (PARI) a(n)=2^(n-1)*(2^n+7)
%o A257272 (Magma) [2^(n-1)*(2^n+7): n in [0..25]]; // _Vincenzo Librandi_, Apr 27 2015
%o A257272 (PARI) Vec((4-15*x)/((1-4*x)*(1-2*x)) + O(x^100)) \\ _Colin Barker_, Apr 27 2015
%Y A257272 Cf. A000079, A007582, A028403, A256873, A257273, A256871.
%Y A257272 Cf. A168415, A057195, A104066, A125247.
%K A257272 nonn,easy
%O A257272 0,1
%A A257272 _M. F. Hasler_, Apr 27 2015