Number of permutations of 1..n in which every pair of adjacent numbers are relatively prime.
A076220
Number of permutations of 1..n in which every pair of adjacent numbers are relatively prime.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =6a(4) =12a(5) =72a(6) =72a(7) =864a(8) =1728a(9) =13824a(10) =22032a(11) =555264a(12) =476928a(13) =17625600a(14) =29599488a(15) =321115392a(16) =805146624a(17) =46097049600a(18) =36481536000
External references
- oeis: A076220