# A005438 (b-file synthesized from sequence entry) 1 1 2 1 3 5 4 10 5 56 6 178 7 1202 8 5296 9 42272 10 238816 11 2204480 12 15214480 13 159575936 14 1301989648 15 15299174672 16 144118832896 17 1875796977152 18 20040052293376 19 286222128454400 20 3419989086092800 21 53183132405282816 22 702831038438522368