# A001277 (b-file synthesized from sequence entry) 2 1 3 3 4 12 5 56 6 321 7 2175 8 17008 9 150504 10 1485465 11 16170035 12 192384876 13 2483177808 14 34554278857 15 515620794591 16 8212685046336 17 139062777326000 18 2494364438359953 19 47245095998005059 20 942259727190907180 21 19737566982241851720 22 433234326593362631601 23 9943659797649140568863