# A084537 (b-file synthesized from sequence entry) 0 1 1 1 2 3 3 7 4 13 5 21 6 31 7 43 8 57 9 73 10 91 11 111 12 133 13 157 14 183 15 211 16 241 17 273 18 307 19 343 20 381 21 421