Triangular array read by rows: a(n,k) = Sum_{d|k} mu(d)*U(n,k/d) if k|n else 0, where U(n,k) = A047916(n,k) (1<=k<=n).
A047918
Triangular array read by rows: a(n,k) = Sum_{d|k} mu(d)*U(n,k/d) if k|n else 0, where U(n,k) = A047916(n,k) (1<=k<=n).
Terms
- a(0) =1a(1) =2a(2) =0a(3) =6a(4) =0a(5) =0a(6) =8a(7) =0a(8) =0a(9) =16a(10) =20a(11) =0a(12) =0a(13) =0a(14) =100a(15) =12a(16) =24a(17) =36a(18) =0a(19) =0a(20) =648a(21) =42a(22) =0a(23) =0a(24) =0a(25) =0a(26) =0a(27) =4998a(28) =32a(29) =32
External references
- oeis: A047918