Number of (s(0), s(1), ..., s(n)) such that s(0) = 0, |s(i) - s(i-1)| = 1 for i = 1,2,3; |s(i) - s(i-1)| <= 1 for i >= 4, s(n) = 3; also a(n) = T(n,n-3), where T is the array defined in A026082.
A026086
Number of (s(0), s(1), ..., s(n)) such that s(0) = 0, |s(i) - s(i-1)| = 1 for i = 1,2,3; |s(i) - s(i-1)| <= 1 for i >= 4, s(n) = 3; also a(n) = T(n,n-3), where T is the array defined in A026082.
Terms
- a(0) =1a(1) =6a(2) =16a(3) =52a(4) =156a(5) =475a(6) =1429a(7) =4293a(8) =12853a(9) =38413a(10) =114621a(11) =341639a(12) =1017407a(13) =3027909a(14) =9007017a(15) =26783331a(16) =79622595a(17) =236662764a(18) =703350798a(19) =2090179494a(20) =6211285598a(21) =18457764317a(22) =54851312871a(23) =163009822939a(24) =484469104651
External references
- oeis: A026086