Number of sequences s of length n, with s[1]=1, s[2]=1, s[3]=1, s[k-1] <=s[k] <= s[k-1]+s[k-2]+s[k-3] (s is called a sub-tribonacci sequence of length n).
A128094
Number of sequences s of length n, with s[1]=1, s[2]=1, s[3]=1, s[k-1] <=s[k] <= s[k-1]+s[k-2]+s[k-3] (s is called a sub-tribonacci sequence of length n).
Terms
- a(0) =1a(1) =3a(2) =9a(3) =36a(4) =228a(5) =2196a(6) =33901a(7) =862503a(8) =36346723a(9) =2564238411a(10) =304902857694
External references
- oeis: A128094