a(i)=a(i-1)+a(j_1)*a(j_2) {where j_1+j_2=i-1, j_1 <= q j_2} + a(j_1)*a(j_2)*a(j_3) {where j_1+j_2+j_3=i-1, j_1 <= q j_2 <= q j_3} +...+ a(1)^{i-1}.
A027881
a(i)=a(i-1)+a(j_1)*a(j_2) {where j_1+j_2=i-1, j_1 <= q j_2} + a(j_1)*a(j_2)*a(j_3) {where j_1+j_2+j_3=i-1, j_1 <= q j_2 <= q j_3} +...+ a(1)^{i-1}.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =4a(4) =9a(5) =20a(6) =51a(7) =121a(8) =321a(9) =826a(10) =2186a(11) =5789a(12) =16114a(13) =42449a(14) =118281a(15) =328425a(16) =908933a(17) =2510553a(18) =7138324a(19) =19869748
External references
- oeis: A027881