120680

Appears in sequences

• Numbers k such that k and k+1 have the same sum of squarefree divisors, or sqf(k) = sqf(k+1), where sqf(k) = A048250(k).at n=30A063964
• Numbers k such that 16 plus the k-th triangular number is a perfect square.at n=12A154146
• Number of n X 4 0..1 arrays with no element equal to more than two of its horizontal, vertical and antidiagonal neighbors and with new values introduced in order 0 sequentially upwards.at n=10A280600
• Numbers k such that k and k+1 are both in A376616.at n=30A376793