Number of length n 1..(1+1) arrays with every leading partial sum divisible by 2, 3, 5 or 7.

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =16a(5) =27a(6) =33a(7) =35a(8) =45a(9) =60a(10) =68a(11) =80a(12) =106a(13) =142a(14) =211a(15) =343a(16) =504a(17) =637a(18) =790a(19) =1130a(20) =1763a(21) =2609a(22) =3568a(23) =4642a(24) =5797a(25) =7056a(26) =8768a(27) =11568a(28) =16417a(29) =24675