# A148431 (b-file synthesized from sequence entry) 0 1 1 1 2 2 3 5 4 19 5 60 6 227 7 809 8 3310 9 12663 10 53248 11 213217 12 918373 13 3796553 14 16616890 15 70310328 16 311537659 17 1341681580 18 6001753284 19 26205738839 20 118120354572 21 521464321540 22 2365096085563 23 10535212139384 24 48029306987720 25 215539833379686 26 986915535822941 27 4456681940039117 28 20482312775594355