a(n) = number of regions in the configuration A290447(n).

Terms

a(0) =0a(1) =1a(2) =3a(3) =7a(4) =15a(5) =30a(6) =56a(7) =98a(8) =161a(9) =250a(10) =370a(11) =536a(12) =748a(13) =1027a(14) =1379a(15) =1807a(16) =2320a(17) =2954a(18) =3702a(19) =4604a(20) =5652a(21) =6852a(22) =8239a(23) =9858a(24) =11683a(25) =13748a(26) =16086a(27) =18700a(28) =21604a(29) =24887