# A158784 (b-file synthesized from sequence entry) 0 1 1 4 2 16 3 72 4 288 5 1168 6 5184 7 20768 8 85120 9 373312 10 1499392 11 6194304 12 26890752 13 108349696 14 450216960 15 1937707520 16 7834814464 17 32689300480 18 139682910208 19 566806726656 20 2371481051136 21 10073319706624 22 41018592608256