Number of distinct quadratic residues mod 5^n.

Terms

a(0) =1a(1) =3a(2) =11a(3) =53a(4) =261a(5) =1303a(6) =6511a(7) =32553a(8) =162761a(9) =813803a(10) =4069011a(11) =20345053a(12) =101725261a(13) =508626303a(14) =2543131511a(15) =12715657553a(16) =63578287761a(17) =317891438803