# A128656 (b-file synthesized from sequence entry) 1 2 2 8 3 44 4 240 5 1248 6 6224 7 30052 8 141536 9 653744 10 2973072 11 13351192 12 59333408 13 261378944 14 1142885664 15 4965331028 16 21452209600 17 92230169232 18 394819386896 19 1683663903016 20 7155148746912 21 30313584232640 22 128067598573408