151823

Appears in sequences

• a(n) = p^2*(p^2+2*p-1)/2, where p = prime(n).at n=8A229738
• a(n) = q^2*(q^2+2*q-1)/2, where q = n-th prime power A000961(n).at n=13A229739
• a(n) = (n^4 + 2*n^3 - n^2)/2.at n=23A255499
• Odd numbers k such that phi(k) = phi(k+2), where phi is the Euler totient function (A000010).at n=13A333741