a(n) = number of (s(0), s(1), ..., s(n)) such that s(i) is an integer, s(0) = 0, |s(1)| = 1, |s(i) - s(i-1)| <= 1 for i >= 2, s(n) = 3. Also a(n) = T(n,n-3), where T is the array defined in A025177.
A025181
a(n) = number of (s(0), s(1), ..., s(n)) such that s(i) is an integer, s(0) = 0, |s(1)| = 1, |s(i) - s(i-1)| <= 1 for i >= 2, s(n) = 3. Also a(n) = T(n,n-3), where T is the array defined in A025177.
Terms
- a(0) =1a(1) =3a(2) =11a(3) =35a(4) =111a(5) =343a(6) =1050a(7) =3186a(8) =9615a(9) =28897a(10) =86592a(11) =258908a(12) =772863a(13) =2304225a(14) =6863496a(15) =20429784a(16) =60779403a(17) =180751617a(18) =537386595a(19) =1597372371a(20) =4747537641a(21) =14108988509a(22) =41928203694a(23) =124598731750a(24) =370279082745
External references
- oeis: A025181