# A121648 (b-file synthesized from sequence entry) 0 1 1 1 2 1 3 4 4 9 5 25 6 64 7 256 8 729 9 2601 10 7921 11 28900 12 90000 13 318096 14 1016064 15 3888784 16 12694969 17 46881409 18 155825289 19 592435600 20 1987643889 21 7408217041 22 25153960000 23 95823678916 24 327811212304 25 1227814692624 26 4234507915264