17961

Appears in sequences

• Record values in A079300 (number of shortest addition chains of n).at n=14A118387
• Numbers n such that prime(n) and phi(n) have the same decimal digits.at n=37A243462
• Numbers k such that k![4] - 16 is prime, where k![4] = A007662(k) = quadruple factorial.at n=34A329166
• Semiprimes of the form k^2 + 5.at n=40A361696
• a(n) is the start of the least run of exactly n consecutive positive numbers with strictly decreasing values of A177329, or -1 if no such run exists.at n=7A374674