# A356837 (b-file synthesized from sequence entry) 0 1 1 20 2 260 3 3212 4 39470 5 484760 6 5953532 7 73117640 8 897985850 9 11028509072 10 135445355180 11 1663456422080 12 20429547136382 13 250903113935780 14 3081437496506420 15 37844317258279532 16 464780593592780450 17 5708148959489987900 18 70103969470537620692 19 860973771077827270580