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 A096977 #18 Sep 08 2022 08:45:14
%S A096977 0,1,2,11,36,157,598,2447,9672,38913,155194,621683,2484908,9943269,
%T A096977 39765790,159077719,636281744,2545185225,10180624386,40722730555,
%U A096977 162890456180,651562756781,2606249162982,10425000380191,41699994064216
%N A096977 a(n) = 4*a(n-1) + 3*a(n-2) - 14*a(n-3) + 8*a(n-4).
%C A096977 Original name was: A Jacobsthal summation.
%C A096977 The convolution of A024000 and A003683. Inverse binomial transform is A055275, with interpolated zeros.
%H A096977 Vincenzo Librandi, <a href="/A096977/b096977.txt">Table of n, a(n) for n = 0..1000</a>
%H A096977 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,3,-14,8).
%F A096977 G.f.: x*(1-2*x)/((1-x)^2*(1+2*x)*(1-4*x)).
%F A096977 a(n) = 4*4^n/27 - 4*(-2)^n/27 + n/9.
%F A096977 a(n) = Sum_{k=0..n} A001045(k)^2.
%F A096977 a(n) = 4*a(n-1) + 3*a(n-2) - 14*a(n-3) + 8*a(n-4).
%t A096977 LinearRecurrence[{4,3,-14,8},{0,1,2,11},30] (* _Harvey P. Dale_, Jul 01 2015 *)
%o A096977 (Magma) [4*4^n/27-4*(-2)^n/27+n/9: n in [0..30]]; // _Vincenzo Librandi_, Jul 01 2011
%o A096977 (PARI) a(n)=(4*4^n-4*(-2)^n+3*n)/27 \\ _Charles R Greathouse IV_, Jul 01 2011
%Y A096977 Cf. A001654.
%K A096977 easy,nonn
%O A096977 0,3
%A A096977 _Paul Barry_, Jul 17 2004