Partial sums of A213709.

Terms

a(0) =0a(1) =1a(2) =2a(3) =4a(4) =7a(5) =12a(6) =21a(7) =38a(8) =68a(9) =122a(10) =220a(11) =399a(12) =729a(13) =1343a(14) =2493a(15) =4655a(16) =8727a(17) =16405a(18) =30901a(19) =58319a(20) =110298a(21) =209098a(22) =397407a(23) =757296a(24) =1446945a(25) =2771951a(26) =5323982a(27) =10250571a(28) =19780122a(29) =38243220