# A124004 (b-file synthesized from sequence entry) 0 1 1 4 2 12 3 56 4 244 5 1396 6 8200 7 55092 8 390216 9 3005288 10 24571056 11 212258216 12 1939879668 13 18429618408 14 184041761768 15 1891831332208 16 20301171282452 17 222742563853912 18 2534535926617852 19 29335558770589276 20 349980362625040712 21 4228388321175157140