The number of permutations of {1,1,1,2,2,2,...,n,n,n} such that each triple of k's (k=1..n) is equally spaced with b(k) other elements in between and b(1) >= b(2) >= ... >= b(n).
A332748
The number of permutations of {1,1,1,2,2,2,...,n,n,n} such that each triple of k's (k=1..n) is equally spaced with b(k) other elements in between and b(1) >= b(2) >= ... >= b(n).
Terms
- a(0) =1a(1) =1a(2) =4a(3) =18a(4) =124a(5) =738a(6) =7464a(7) =55890a(8) =668778a(9) =7030210a(10) =90713844a(11) =1054221258a(12) =18597735744a(13) =242795838520
External references
- oeis: A332748