# A278995 (b-file synthesized from sequence entry) 1 1 2 -2 3 -4 4 8 5 16 6 -32 7 -64 8 128 9 4864 10 -9728 11 -37888 12 223232 13 446464 14 -1482752 15 5586944 16 -11173888 17 -56557568 18 -2490368 19 -4980736 20 472383488 21 -10851713024 22 21703426048 23 90592772096 24 -263779778560 25 -10023631585280 26 -4209210589970432 27 -50541367159422976