# A002498 (b-file synthesized from sequence entry) 1 3 2 7 3 12 4 19 5 30 6 43 7 49 8 53 9 70 10 89 11 112 12 141 13 172 14 209 15 250 16 293 17 301 18 348 19 368 20 421 21 480