# A331538 (b-file synthesized from sequence entry) 0 0 1 1 2 3 3 16 4 147 5 1756 6 25910 7 453594 8 9184091 9 211075288 10 5427652794 11 154380255250 12 4812088559014 13 163110595450466 14 5973198636395003 15 235010723141883563 16 9886231689434154971 17 442799642855527526848 18 21038043034795035118742 19 1056802542597653892224802 20 55962024535834950971809754