227180

Appears in sequences

• a(0)=0, a(1)=1, a(n) = a(n-1) + 2^(n-3)*a(n-2).at n=10A165901
• Limit of rows, when read in reverse, of triangle A227372.at n=31A227377
• Smallest number k > 0 such that sigma(x) and sigma(x)+2 are both prime, where x = (6k+1)^(6n+4), or -1 if no such k exists.at n=14A275237