Row sums of triangle A120898 (cascadence of 1+2x+x^2).

Terms

a(0) =1a(1) =5a(2) =23a(3) =103a(4) =450a(5) =1932a(6) =8196a(7) =34468a(8) =143997a(9) =598463a(10) =2476936a(11) =10216818a(12) =42023225a(13) =172436363a(14) =706132290a(15) =2886574198a(16) =11781962631a(17) =48025519977a(18) =195530083266a(19) =795241236228