# A052791 (b-file synthesized from sequence entry) 0 0 1 0 2 0 3 6 4 72 5 540 6 3240 7 17010 8 81648 9 367416 10 1574640 11 6495390 12 25981560 13 101328084 14 386889048 15 1450833930 16 5356925280 17 19514513520 18 70252248672 19 250273635894 20 883318714920 21 3091615502220 22 10739295955080 23 37050571045026 24 127030529297232 25 433058622604200 26 1468633589701200