A107250 Diagonal sums of number array A107249.
1, 1, 2, 3, 5, 9, 16, 30, 54, 104, 191, 372, 692, 1357, 2550, 5021, 9508, 18773, 35766, 70755, 135461, 268365, 515849, 1023092, 1973159, 3916831, 7575470, 15048428, 29175431, 57990158, 112665488, 224048847, 436089113, 867581269, 1691392152
Offset: 0
Formula
a(n)=sum{k=0..floor(n/2), C(floor((2n-3k-2)/2), floor((n-2k)/2))}