Number of ways to change three non-identical letters in the word aabbccdd..., where there are n types of letters.

A102860

Number of ways to change three non-identical letters in the word aabbccdd..., where there are n types of letters.

Terms

    a(0) =0a(1) =16a(2) =64a(3) =160a(4) =320a(5) =560a(6) =896a(7) =1344a(8) =1920a(9) =2640a(10) =3520a(11) =4576a(12) =5824a(13) =7280a(14) =8960a(15) =10880a(16) =13056a(17) =15504a(18) =18240a(19) =21280a(20) =24640a(21) =28336a(22) =32384a(23) =36800a(24) =41600a(25) =46800a(26) =52416a(27) =58464a(28) =64960a(29) =71920

External references