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 A276122 #30 Mar 20 2017 11:49:03
%S A276122 1,1,1,4,22,526,69427,219111589,91273561736491,
%T A276122 119994570874632853695766,65713991236617279734602790963627271046,
%U A276122 47311933073383646516067037755547920981262829886906923065810924
%N A276122 a(0) = a(1) = a(2) = 1; for n > 2, a(n) = (a(n-1)^2+a(n-2)^2+a(n-1)+a(n-2))/a(n-3).
%H A276122 Seiichi Manyama, <a href="/A276122/b276122.txt">Table of n, a(n) for n = 0..16</a>
%F A276122 a(n) = 6*a(n-1)*a(n-2)-a(n-3)-1.
%F A276122 a(n) ~ 1/6 * c^(phi^n), where c = 2.059783590102273... and phi = A001622 = (1+sqrt(5))/2 is the golden ratio. - _Vaclav Kotesovec_, Mar 20 2017
%t A276122 RecurrenceTable[{a[n] == (a[n - 1]^2 + a[n - 2]^2 + a[n - 1] + a[n - 2])/a[n - 3], a[0] == a[1] == a[2] == 1}, a, {n, 0, 11}] (* _Michael De Vlieger_, Aug 21 2016 *)
%Y A276122 Cf. A064098, A072881, A101879, A165903.
%K A276122 nonn
%O A276122 0,4
%A A276122 _Bruno Langlois_, Aug 21 2016
%E A276122 a(10) corrected by _Seiichi Manyama_, Aug 21 2016