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 A135166 #21 Sep 08 2022 08:45:32
%S A135166 2,11,69,449,2961,19721,132609,899609,6149121,42287561,292182849,
%T A135166 2025979769,14084900481,98108127401,684321821889,4778064771929,
%U A135166 33385475479041,233393324431241,1632227908017729,11417967509964089,79887630243516801,559022690783231081,3912205202997138369
%N A135166 a(n) = 7^n + 5^n - 3^n + 2^n.
%C A135166 Constants are the prime numbers in decreasing order.
%H A135166 G. C. Greubel, <a href="/A135166/b135166.txt">Table of n, a(n) for n = 0..1000</a>
%H A135166 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (17, -101, 247, -210).
%F A135166 a(n) = 7^n + 5^n - 3^n + 2^n.
%F A135166 a(0)=2, a(1)=11, a(2)=69, a(3)=449, a(n) = 17*a(n-1) - 101*a(n-2) + 247*a(n-3) - 210*a(n-4). - _Harvey P. Dale_, Feb 01 2013
%F A135166 From _G. C. Greubel_, Sep 30 2016: (Start)
%F A135166 G.f.: (2 - 23*x + 84*x^2 - 107*x^3)/((1 -2*x)*(1 -3*x)*(1 -5*x)*(1 -7*x)).
%F A135166 E.g.f.: exp(7*x) + exp(5*x) - exp(3*x) + exp(2*x). (End)
%e A135166 a(4) = 2961 because 7^4 = 2401, 5^4 = 625, 3^4 = 81, 2^4 = 16 and we can write 2401 + 625 - 81 + 16 = 2961.
%t A135166 Table[7^n+5^n-3^n+2^n,{n,0,30}] (* or *) LinearRecurrence[ {17,-101,247,-210},{2,11,69,449},30] (* _Harvey P. Dale_, Feb 01 2013 *)
%o A135166 (Magma)[7^n+5^n-3^n+2^n: n in [0..50]] // _Vincenzo Librandi_, Dec 14 2010
%o A135166 (PARI) a(n)=7^n+5^n-3^n+2^n \\ _Charles R Greathouse IV_, Sep 30 2016
%Y A135166 Cf. A000079, A000244, A000351, A000420, A001047, A074527, A007689, A135158, A135159, A135160.
%K A135166 easy,nonn
%O A135166 0,1
%A A135166 _Omar E. Pol_, Nov 21 2007
%E A135166 More terms from _Vincenzo Librandi_, Dec 14 2010