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 A087290 #24 Aug 24 2024 21:46:04
%S A087290 8,56,488,4376,39368,354296,3188648,28697816,258280328,2324522936,
%T A087290 20920706408,188286357656,1694577218888,15251194969976,
%U A087290 137260754729768,1235346792567896,11118121133111048,100063090197999416,900567811781994728,8105110306037952536
%N A087290 Number of pairs of polynomials (f,g) in GF(3)[x] satisfying deg(f) <= n, deg(g) <= n and gcd(f,g) = 1.
%C A087290 An unpublished result due to Stephen Suen, _David desJardins_, and W. Edwin Clark. This is the case k = 2, q = 3 of their formula q^((n+1)*k) * (1 - 1/q^(k-1) + (q-1)/q^((n+1)*k)) for the number of ordered k-tuples (f_1, ..., f_k) of polynomials in GF(q)[x] such that deg(f_i) <= n for all i and gcd(f_1, ..., f_k) = 1.
%H A087290 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (10,-9).
%F A087290 a(n) = 2*3^(2*n+1) + 2.
%F A087290 a(n) = 10*a(n-1) - 9*a(n-2), a(0)=8, a(1)=56. - _Harvey P. Dale_, Mar 07 2012
%F A087290 G.f.: 8*(1-3*x)/((1-x)*(1-9*x)). - _Colin Barker_, Apr 16 2012
%e A087290 a(0) = 8 since there are eight pairs, (0,1), (0,2), (1,0), (1,1), (1,2), (2,0), (2,1), (2,2) of polynomials (f,g) in GF(3)[x] of degree at most 0 such that gcd(f,g) = 1.
%t A087290 2*3^(2Range[0,30]+1)+2 (* or *) LinearRecurrence[{10,-9},{8,56},30] (* _Harvey P. Dale_, Mar 07 2012 *)
%Y A087290 Cf. A087289, A087291, A087292.
%K A087290 easy,nonn
%O A087290 0,1
%A A087290 _W. Edwin Clark_, Aug 29 2003
%E A087290 More terms from _Harvey P. Dale_, Mar 07 2012