Number of ways of folding a 3 X n strip of stamps.

A001416

Number of ways of folding a 3 X n strip of stamps.

Terms

    a(0) =1a(1) =6a(2) =60a(3) =1368a(4) =15552a(5) =201240a(6) =2016432a(7) =21582624a(8) =201060768a(9) =1944012744a(10) =17257455960a(11) =156760071600

External references