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 A129550 #4 Sep 22 2013 15:58:10 %S A129550 1,1,8,20,98,293,1128,3409,10846,30480,84652,217677,544312,1289225, %T A129550 2961626,6528284,13980717,28963980,58464510,114806429,220298632, %U A129550 412950779,758418342,1365044296,2412766496,4189995629,7159916414 %N A129550 Number of real polynomial invariants for the action of 4 copies of U(2) on the fourth tensor power of C^2. %D A129550 M. W. Hero and J. F. Willenbring, Stable Hilbert series as related to the measurement of quantum entanglement, Discrete Math., 309 (2010), 6508-6514. %D A129550 Nolan R. Wallach, The Hilbert series for measures of entanglement in 4 qubits, Acta Appl. Math. 86(2005),203-220. %F A129550 G.f.: (R(q) + q^76*R(1/q))/((1 - q^2)*(1 - q^4)^7*(1 - q^6)^6*(1 - q^8)^4*(1 - q^10)) where R(q) = 1 + 6*q^6 + 46*q^8 + 110*q^10 + 344*q^12 + 844*q^14 + 2154*q^16 + 4606*q^18 + 9397*q^20 + 16848*q^22 + 28747*q^24 + 44580*q^26 + 65366*q^28 + 88036*q^30 + 111909*q^32 + 131368*q^34 + 145676*q^36 + 149860/2*q^38. %Y A129550 Cf. A129548, A129549. %K A129550 nonn %O A129550 0,3 %A A129550 _Mike Zabrocki_, Apr 20 2007