121397

Appears in sequences

• Concatenations C1 and C2 and C3 and C4 are all prime (see the comment lines).at n=25A034819
• Expansion of (1+x)^2/(1-2x^2+x^3).at n=30A113312
• a(n) = Fibonacci(n) + 4.at n=26A157727
• Number of 3Xn 0..1 arrays with every element equal to 0 or 1 horizontally or antidiagonally adjacent elements, with upper left element zero.at n=22A301792
• Number of nX4 0..1 arrays with every element unequal to 0, 2, 3 or 6 king-move adjacent elements, with upper left element zero.at n=24A304137