174063616

Appears in sequences

• Number of subsets of {1,.., n} containing at least one twin prime pair.at n=27A089828
• Number of (n+1) X (n+1) 0..1 arrays with the number of clockwise edge increases in every 2 X 2 subblock differing from each horizontal or vertical neighbor.at n=20A205186
• a(n) = 2^(n-2) * prime(n).at n=22A239885