194145

Appears in sequences

• a(6n+k) = 3a(6n+k-1)-3a(6n+k-2)+2a(6n+k-3), k = 0, 1, 3, 4, 5; a(6n+2) = 3a(6n+1)-3a(6n). a(0) = a(1) = 0, a(2) = 1.at n=21A132658
• a(n) = Sum_{k=1..n} k^2 * 4^(n-k).at n=9A368529