# A005553 (b-file synthesized from sequence entry) 4 6 5 40 6 174 7 644 8 2268 9 8020 10 28666 11 103696 12 379450 13 1402276 14 5227366 15 19633732 16 74230146 17 282273744 18 1078902168 19 4142578832 20 15970882784 21 61798680076 22 239921541412 23 934258870200 24 3648030627298 25 14280474288676