# A165910 (b-file synthesized from sequence entry) 1 1 2 4 3 18 4 62 5 210 6 666 7 2063 8 6226 9 18484 10 54100 11 156620 12 449268 13 1278981 14 3617544 15 10175590 16 28485218 17 79406350 18 220536910 19 610487875 20 1684974790 21 4638298536 22 12737460744 23 34902844728 24 95449821672 25 260554112425 26 710056257196