120994

Appears in sequences

• Numbers n such that n-tau(n), phi(n) and n form a Heronian triangle, where tau=A000005 is the number of divisors and phi=A000010 the totient.at n=8A268281
• a(n) = 9a(n-1) - 9a(n-2) + a(n-3).at n=5A272365