# A274019 (b-file synthesized from sequence entry) 0 1 1 4 2 10 3 23 4 66 5 192 6 636 7 2092 8 7228 9 25175 10 89212 11 318808 12 1150444 13 4177908 14 15268494 15 56078527 16 206903020 17 766342160 18 2848351388 19 10619472284 20 39702648534 21 148806583111 22 558999381656 23 2104255629608 24 7936108068008 25 29982733437844 26 113456750715426 27 429964269551767 28 1631663320986086