a(0) = 1; for n > 0, a(n) = a(n-1) + floor(sqrt(a(n-1))).

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =6a(5) =8a(6) =10a(7) =13a(8) =16a(9) =20a(10) =24a(11) =28a(12) =33a(13) =38a(14) =44a(15) =50a(16) =57a(17) =64a(18) =72a(19) =80a(20) =88a(21) =97a(22) =106a(23) =116a(24) =126a(25) =137a(26) =148a(27) =160a(28) =172a(29) =185