# A277406 (b-file synthesized from sequence entry) 0 1 1 2 2 9 3 76 4 1100 5 25176 6 846132 7 39321696 8 2413753344 9 189030205440 10 18383301319680 11 2172771551093760 12 306662748175330560 13 50933260598106862080 14 9832247390118248121600 15 2182733403365330313523200 16 552134185815355910465126400 17 157863713952139655599757721600 18 50654908373638564216229105664000