A152808 Column 3 of triangle A152798; a(n) = A152798(n+3,3).
1, 1, 4, 10, 29, 93, 310, 1106, 4205, 16912, 71858, 321921, 1516429, 7493126, 38758968, 209453249, 1180293354, 6923457745, 42206892713, 267002169884, 1750266527588, 11873506488390, 83253781992093, 602667751464027
Offset: 0