Number of reversible strings with n beads using a maximum of six different colors.
A056308
Number of reversible strings with n beads using a maximum of six different colors.
Terms
- a(0) =1a(1) =6a(2) =21a(3) =126a(4) =666a(5) =3996a(6) =23436a(7) =140616a(8) =840456a(9) =5042736a(10) =30236976a(11) =181421856a(12) =1088414496a(13) =6530486976a(14) =39182222016a(15) =235093332096
External references
- oeis: A056308