812041860domain: NAppears in sequencesa(n) = number of integer strings s(0),...,s(n) counted by array T in A026386 that have s(n)=0; also a(n) = T(2n,n).at n=13A026387T(n,[ n/2 ]), where T is the array in A026386.at n=27A026392a(0)=1; for n>0, a(n) = 2*5^(n-1) - (1/2)*Sum_{i=1..n-1} a(i)*a(n-i).at n=14A085362