Number of length n words on the alphabet {a,b,c,d,e} that do not contain exactly one a and exactly one b.
A387680
Number of length n words on the alphabet {a,b,c,d,e} that do not contain exactly one a and exactly one b.
Terms
- a(0) =1a(1) =5a(2) =23a(3) =107a(4) =517a(5) =2585a(6) =13195a(7) =67919a(8) =349801a(9) =1795661a(10) =9175135a(11) =46662995a(12) =236346157a(13) =1193068193a(14) =6006793363a(15) =30182770295a(16) =151439978065a(17) =759036550421
External references
- oeis: A387680