A047108 T(n,n+3), array T as in A047100.
1, 4, 15, 57, 215, 812, 3083, 11750, 44934, 172401, 663370, 2559008, 9894006, 38331115, 148770379, 578346672, 2251636041, 8777816518, 34261079538, 133873978089, 523638632149, 2050085911219, 8033148700174, 31502487793694
Offset: 0