# A107584 (b-file synthesized from sequence entry) 0 1 1 0 2 8 3 52 4 240 5 1004 6 4072 7 16356 8 65504 9 262108 10 1048536 11 4194260 12 16777168 13 67108812 14 268435400 15 1073741764 16 4294967232 17 17179869116 18 68719476664 19 274877906868 20 1099511627696 21 4398046511020 22 17592186044328 23 70368744177572 24 281474976710560 25 1125899906842524