%N Row 4 of array in A047666.
%C In this sequence if we do a forward difference, then the 3rd forward difference when considered as a sequence will be an arithmetic progression with common difference 8. [Gopalakrishnan (gopala498(AT)yahoo.co.in), Jun 05 2010]
%F a(n) = (1/3) * (n^4 + 8n^2 + 3).
%F G.f.: x*(4 - 3*x + 7*x^2 - x^3 + x^4)/(1-x)^5. - Maksym Voznyy (voznyy(AT)mail.ru), Jul 27 2009 [corrected by _R. J. Mathar_, Sep 16 2009]
%A _N. J. A. Sloane_