Number of subsets of {1,2,3,...,n} that sum to 0 mod 10.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =4a(6) =7a(7) =13a(8) =26a(9) =52a(10) =104a(11) =206a(12) =410a(13) =820a(14) =1640a(15) =3280a(16) =6556a(17) =13108a(18) =26216a(19) =52432a(20) =104864a(21) =209720a(22) =419432a(23) =838864a(24) =1677728a(25) =3355456a(26) =6710896a(27) =13421776a(28) =26843552a(29) =53687104