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 A099359 #21 Feb 16 2025 08:32:55
%S A099359 6,25,123,727,4911,35935,274623,2146687,16974591,135005695,1076890623,
%T A099359 8602523647,68769820671,549957165055,4398851866623,35187593412607,
%U A099359 281487861809151,2251851353686015,18014604668698623,144116012711149567,1152924803144876031
%N A099359 a(n) = (2^n + 1)^3 - 2.
%H A099359 Colin Barker, <a href="/A099359/b099359.txt">Table of n, a(n) for n = 0..1000</a>
%H A099359 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/integersequenceprimes.html">Integer sequence primes</a>.
%H A099359 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (15,-70,120,-64).
%F A099359 From _Colin Barker_, Jan 10 2017: (Start)
%F A099359 a(n) = (3*2^n + 3*4^n + 8^n - 1).
%F A099359 a(n) = 15*a(n-1) - 70*a(n-2) + 120*a(n-3) - 64*a(n-4) for n>3.
%F A099359 G.f.: (6 - 65*x + 168*x^2 - 88*x^3) / ((1 - x)*(1 - 2*x)*(1 - 4*x)*(1 - 8*x)).
%F A099359 (End)
%e A099359 (2^1 + 1)^3 - 2 = 25.
%t A099359 Table[(2^n + 1)^3 - 2, {n, 19}] (* _Robert G. Wilson v_, Nov 23 2004 *)
%o A099359 (PARI) a(n)=(2^n+1)^3-2 \\ _Charles R Greathouse IV_, Feb 19 2016
%o A099359 (PARI) Vec((6 - 65*x + 168*x^2 - 88*x^3) / ((1 - x)*(1 - 2*x)*(1 - 4*x)*(1 - 8*x)) + O(x^30)) \\ _Colin Barker_, Jan 10 2017
%Y A099359 Cf. A098878.
%K A099359 nonn,easy
%O A099359 0,1
%A A099359 _Parthasarathy Nambi_, Nov 16 2004
%E A099359 More terms from _Robert G. Wilson v_, Nov 23 2004