23796335

Appears in sequences

• a(n) = -a(n-1) + 2a(n-2) - a(n-3), with a(0) = 0, a(1) = 1, a(2) = -3.at n=23A135019
• a(1) = 1, a(n) = Sum_{k=1..n} (k mod 3) * a(n-k) for n >= 2.at n=23A141685