183760

Appears in sequences

• Numbers k such that 3*10^k + 1*R_k is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=24A056704
• Number of 4-step knight's tours on an (n+2) X (n+2) board summed over all starting positions.at n=22A186853
• a(n) = floor(x(n)) where x(n) = (frac(x(n-1))+1)*floor(x(n-1)) and x(1) = Pi.at n=30A339412