a(n) = Sum_{d|n} A007955(d) * A008683(n/d) = Sum_{d|n} A007955(d) * mu(n/d), where A007955(m) = number of divisors of m.
A174940
a(n) = Sum_{d|n} A007955(d) * A008683(n/d) = Sum_{d|n} A007955(d) * mu(n/d), where A007955(m) = number of divisors of m.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =6a(4) =4a(5) =32a(6) =6a(7) =56a(8) =24a(9) =94a(10) =10a(11) =1686a(12) =12a(13) =188a(14) =218a(15) =960a(16) =16a(17) =5772a(18) =18a(19) =7894a(20) =432a(21) =472a(22) =22a(23) =329992a(24) =120a(25) =662a(26) =702a(27) =21750a(28) =28a(29) =809648
External references
- oeis: A174940