# A138356 (b-file synthesized from sequence entry) 0 1 1 1 2 2 3 4 4 10 5 27 6 82 7 268 8 940 9 3476 10 13448 11 53968 12 223412 13 949535 14 4128594 15 18310972 16 82645012 17 378851428 18 1760998280 19 8288679056 20 39457907128 21 189784872428 22 921472827272 23 4512940614960 24 22279014978544 25 110797225212112