A086952 a(n) = n^2*4^n/4.
0, 1, 16, 144, 1024, 6400, 36864, 200704, 1048576, 5308416, 26214400, 126877696, 603979776, 2835349504, 13153337344, 60397977600, 274877906944, 1241245548544, 5566277615616, 24807731101696, 109951162777600, 484884627849216, 2128654511374336, 9306266417496064, 40532396646334464
Offset: 0
Links
- Index entries for linear recurrences with constant coefficients, signature (12,-48,64).
Formula
G.f.: x*(1 + 4*x)/(1 - 4*x)^3.
E.g.f.: exp(4*x)*x*(1 + 4*x). - Stefano Spezia, Oct 09 2022