# A075156 (b-file synthesized from sequence entry) 0 5 1 6 2 10 3 24 4 70 5 216 6 664 7 2008 8 5998 9 17808 10 52770 11 156360 12 463492 13 1374392 14 4076222 15 12090144 16 35859742 17 106359928 18 315460168 19 935639768 20 2775057510 21 8230670416 22 24411730298 23 72403913480 24 214746249796 25 636926269816