Expansion of 1/(1 - Sum_{i>=1, j>=1, k>=1, l>=1} x^(i*j*k*l)).

Terms

a(0) =1a(1) =1a(2) =5a(3) =13a(4) =47a(5) =133a(6) =443a(7) =1333a(8) =4263a(9) =13143a(10) =41419a(11) =128791a(12) =403815a(13) =1259639a(14) =3941579a(15) =12310299a(16) =38492034a(17) =120271953a(18) =375964616a(19) =1174935195a(20) =3672413322a(21) =11477465221a(22) =35872928244a(23) =112117013835a(24) =350417746650