# A013700 (b-file synthesized from sequence entry) 1 1 2 128 3 6765 4 265720 5 9112264 6 290926848 7 8916942687 8 266668876540 9 7853149169635 10 228982270335000 11 6632994268595136 12 191292945772217856 13 5500214758962096400 14 157819424038439232000 15 4521902974531722618723