121975

Appears in sequences

• Numbers k such that 5^k == -1 (mod k-1).at n=11A055688
• Numbers k such that sigma(sigma(k)-k) = phi(k).at n=19A074875
• a(n) = n*(4*n - 3)*(16*n^2 - 12*n - 3).at n=7A264895