Number of subsets of {1,2,3,...,n} that sum to 0 mod 5.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =4a(5) =8a(6) =14a(7) =26a(8) =52a(9) =104a(10) =208a(11) =412a(12) =820a(13) =1640a(14) =3280a(15) =6560a(16) =13112a(17) =26216a(18) =52432a(19) =104864a(20) =209728a(21) =419440a(22) =838864a(23) =1677728a(24) =3355456a(25) =6710912a(26) =13421792a(27) =26843552a(28) =53687104a(29) =107374208