1299185

Appears in sequences

• a(1)..a(4) = 0,0,0,1; thereafter a(n) = a(n-2)+a(n-3)+2*(d(n-3)+d(n-4)) where d(n) = A238824(n).at n=19A238825
• a(n) = 1 + Sum_{k=0..n-4} binomial(n-3,k) * a(k).at n=17A344491