# A052183 (b-file synthesized from sequence entry) 0 2 1 3 2 12 3 60 4 330 5 1911 6 11424 7 69768 8 432630 9 2713425 10 17168580 11 109390320 12 700939512 13 4512458580 14 29164264320 15 189120846288 16 1229917589262 17 8018580361365 18 52392620853300 19 342991368096300 20 2249282417749290