Number of permutations of the divisors of n that are greater than 1, in which consecutive elements are not coprime and no divisor d may occur later than any divisor e if e < d and A007947(e) = A007947(d). That is, any subset of divisors sharing the same squarefree part occur always in ascending order inside the permutation.
A293900
Number of permutations of the divisors of n that are greater than 1, in which consecutive elements are not coprime and no divisor d may occur later than any divisor e if e < d and A007947(e) = A007947(d). That is, any subset of divisors sharing the same squarefree part occur always in ascending order inside the permutation.
Terms
- a(0) =0a(1) =1a(2) =1a(3) =1a(4) =1a(5) =2a(6) =1a(7) =1a(8) =1a(9) =2a(10) =1a(11) =9a(12) =1a(13) =2a(14) =2a(15) =1a(16) =1a(17) =9a(18) =1a(19) =9a(20) =2a(21) =2a(22) =1a(23) =40a(24) =1a(25) =2a(26) =1a(27) =9a(28) =1a(29) =348
External references
- oeis: A293900