Number of permutations of 4 indistinguishable copies of 1..n arranged in a circle with exactly 2 adjacent element pairs in decreasing order.
A151597
Number of permutations of 4 indistinguishable copies of 1..n arranged in a circle with exactly 2 adjacent element pairs in decreasing order.
Terms
- a(0) =0a(1) =36a(2) =606a(3) =4744a(4) =30850a(5) =186924a(6) =1092966a(7) =6248976a(8) =35154954a(9) =195310900a(10) =1074216814a(11) =5859372696a(12) =31738278546a(13) =170898434364a(14) =915527340150
External references
- oeis: A151597