a(n) gives the number of squares in the n-th iteration of the Harter-Heighway dragon.

Terms

a(0) =0a(1) =0a(2) =0a(3) =1a(4) =4a(5) =11a(6) =30a(7) =78a(8) =205a(9) =546a(10) =1455a(11) =4062a(12) =11192a(13) =31889a(14) =88487a(15) =254594a(16) =710683a(17) =2047705a(18) =5711439a(19) =16455169a(20) =45894868a(21) =132118562a(22) =368149344a(23) =1059171430a(24) =2950384277a(25) =8484556353