# A069699 (b-file synthesized from sequence entry) 1 0 2 1 3 3 4 6 5 10 6 15 7 21 8 28 9 36 10 45 11 55 12 66 13 78 14 91 15 171 16 276 17 378 18 1770 19 2775 20 5778 21 8778