# A167983 (b-file synthesized from sequence entry) 3 96 4 360 5 1440 6 7120 7 37728 8 196488 9 974592 10 4536000 11 19934208 12 82689264 13 322437312 14 1171745280 15 3924079104 16 11964375936 17 32761139328 18 79244294016 19 165800420352 20 291640320576 21 413774810112 22 443415854592 23 318534709248 24 114869295744