# A012739 (b-file synthesized from sequence entry) 0 1 1 -2 2 20 3 -16 4 14096 5 887456 6 126998976 7 21834514688 8 5067177011456 9 1485621376751104 10 540527763829711872 11 238770291840873000960 12 125924968135743519723520 13 78156500138405011699867648