a(n) is the number of sets of natural numbers [a,b,c,d,e] that can be produced with the numbers [0..n] such that the values of all the distinct parenthesized expressions of a-b-c-d-e are different.
A054026
a(n) is the number of sets of natural numbers [a,b,c,d,e] that can be produced with the numbers [0..n] such that the values of all the distinct parenthesized expressions of a-b-c-d-e are different.
Terms
- a(0) =0a(1) =0a(2) =0a(3) =0a(4) =300a(5) =1296a(6) =4116a(7) =9984a(8) =21384a(9) =40800a(10) =72600a(11) =120960a(12) =192660a(13) =294000a(14) =434700a(15) =623616a(16) =873936a(17) =1197504a(18) =1611504a(19) =2131200a(20) =2778300a(21) =3571920a(22) =4538820a(23) =5702400a(24) =7095000a(25) =8744736a(26) =10690056a(27) =12964224a(28) =15612324a(29) =18673200
External references
- oeis: A054026