688905

Appears in sequences

• Number of rooted labeled triangular cacti with 2n+1 nodes (n triangles).at n=4A034940
• a(n) = n*3^n*(4*n - 1)/9.at n=9A086951
• Triangle T(n, k) = binomial(n, k)*A000166(n-k)*k^n with T(0, 0) = 1, read by rows.at n=31A156788
• Number of (n+2) X (1+2) 0..3 arrays with every consecutive three elements in every row and column not having exactly two distinct values, and in every diagonal and antidiagonal having exactly two distinct values, and new values 0 upwards introduced in row major order.at n=28A253018
• Odd exceptional numbers: odd k such that A005179(k) < A037019(k).at n=30A331613
• a(n) is the largest odd positive integer that is abundant and has the same prime signature as A279537(n) or 0 if no such integer exists.at n=64A343330
• A variant of Look and Say sequence (A005150) based on exponents in prime factorization of n (see Comments section for precise definition).at n=28A356008
• Numbers k such that k, A001414(k) and A083345(k) are all multiples of 3, where A001414 is fully additive with a(p) = p, and A083345 is the numerator of the fully additive function with a(p) = 1/p.at n=5A373476