# A037131 (b-file synthesized from sequence entry) 0 0 1 1 2 6 3 28 4 120 5 497 6 2016 7 8140 8 32640 9 130813 10 523776 11 2096133 12 8386580 13 33550335 14 134209524 15 536854528 16 2147450887 17 8589869054 18 34359607310 19 137438691321 20 549755289604 21 2199022206975 22 8796090925052 23 35184367894531 24 140737479966709 25 562949936644106