a(n) = 11^n+5^n-1^n.

Terms

a(0) =1a(1) =15a(2) =145a(3) =1455a(4) =15265a(5) =164175a(6) =1787185a(7) =19565295a(8) =214749505a(9) =2359900815a(10) =25947190225a(11) =285360498735