Number of distinct quadratic residues mod 3^n.

Terms

a(0) =1a(1) =2a(2) =4a(3) =11a(4) =31a(5) =92a(6) =274a(7) =821a(8) =2461a(9) =7382a(10) =22144a(11) =66431a(12) =199291a(13) =597872a(14) =1793614a(15) =5380841a(16) =16142521a(17) =48427562a(18) =145282684a(19) =435848051a(20) =1307544151a(21) =3922632452a(22) =11767897354a(23) =35303692061a(24) =105911076181a(25) =317733228542a(26) =953199685624