# A074035 (b-file synthesized from sequence entry) 1 0 2 1 3 1 4 4 5 12 6 45 7 144 8 512 9 1813 10 6579 11 23808 12 87380 13 322560 14 1198665 15 4473647 16 16777216 17 63160320 18 238612920 19 904200192 20 3435973836 21 13089411609 22 49977848925 23 191219367936 24 733007751680 25 2814749599332 26 10825961287995 27 41699995927744 28 160842843834660