# A055848 (b-file synthesized from sequence entry) 0 1 1 15 2 105 3 495 4 1815 5 5577 6 15015 7 36465 8 81510 9 170170 10 335478 11 629850 12 1133730 13 1967070 14 3304290 15 5393454 16 8580495 17 13339425 18 20309575 19 30341025 20 44549505 21 64382175 22 91695825 23 128849175 24 178811100 25 245286756 26 332863740 27 447180580