252509579303
domain: N
Appears in sequences
- a(n+1) - 3*a(n) + a(n-1) = (2/3)(1+w^(n+1)+w^(2n+2)), where w = exp(2 Pi I / 3).at n=28A071618
- a(n) = 3*a(n-1) + 5*a(n-2) + a(n-3).at n=18A120775
- Half the number of n X 2 binary arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.at n=27A185828
- Indices of triangular numbers (A000217) that are also centered pentagonal numbers (A005891).at n=18A254626
- Smallest nonnegative integer not expressible by the addition and subtraction of fewer than n Lucas numbers.at n=19A364754