Number of length-n 0..4 arrays connected end-around, with no sequence of L<n elements immediately followed by itself (periodic "squarefree").
A215224
Number of length-n 0..4 arrays connected end-around, with no sequence of L<n elements immediately followed by itself (periodic "squarefree").
Terms
- a(0) =5a(1) =20a(2) =60a(3) =240a(4) =720a(5) =2940a(6) =10080a(7) =38640a(8) =140400a(9) =529440a(10) =1956900a(11) =7335840a(12) =27285180a(13) =101960040a(14) =380209980a(15) =1419732000
External references
- oeis: A215224