28919

Appears in sequences

• Numbers k such that sopf(k) + 1 = sopf(k+1), where sopf(k) = A008472(k).at n=22A064111
• Frobenius number of the numerical semigroup generated by four consecutive tetrahedral numbers.at n=14A069761
• Composite numbers k such that phi(k) * psi(k) + 1 is a perfect square, where phi is the Euler totient function (A000010) and psi is the Dedekind psi function (A001615).at n=38A309653