# A091875 (b-file synthesized from sequence entry) 2 5 3 15 4 35 5 115 6 365 7 3215 8 32150 9 321500 10 3215000 11 32150000 12 321500000 13 3215000000 14 32150000000 15 321500000000 16 3215000000000 17 32150000000000 18 321500000000000 19 3215000000000000 20 32150000000000000 21 321500000000000000