a(n) = 2*a(n-1) + 11*a(n-2), a(0) = 0, a(1) = 1.

Terms

a(0) =0a(1) =1a(2) =2a(3) =15a(4) =52a(5) =269a(6) =1110a(7) =5179a(8) =22568a(9) =102105a(10) =452458a(11) =2028071a(12) =9033180a(13) =40375141a(14) =180115262a(15) =804357075a(16) =3589982032a(17) =16027891889a(18) =71545586130a(19) =319397983039