93160

Appears in sequences

• a(n) = number of (s(0),s(1),...,s(n)) such that every s(i) is a nonnegative integer, s(0) = 1, s(n) = 3, |s(1) - s(0)| = 1, |s(i) - s(i-1)| <= 1 for i >= 2. Also a(n) = T(n,n-2), where T is the array in A026120.at n=11A026124
• a(n) = Sum_{k=m..n} T(k,n-k), where m = floor((n+1)/2); a(n) is the n-th diagonal-sum of left justified array T given by A027935.at n=29A027947
• a(n) cannot be prefixed or followed by any digit to form a prime ('empty' prefixes allowed).at n=31A032736
• a(n) cannot be prefixed or followed by any digit to form a prime ('empty' prefixes and suffixes are allowed).at n=21A032738
• Sequence equals its 4th differences shifted by one index.at n=14A137166
• a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) + a(n-4) with a(1) = 1, a(2) = 2, a(3) = 4, and a(4) = 7.at n=19A385106