A120902 Row sums of triangle A120898 (cascadence of 1+2x+x^2).
1, 5, 23, 103, 450, 1932, 8196, 34468, 143997, 598463, 2476936, 10216818, 42023225, 172436363, 706132290, 2886574198, 11781962631, 48025519977, 195530083266, 795241236228, 3231290822280, 13118557603984, 53218706064038
Offset: 0