30991

Appears in sequences

• Numbers k such that k, k+2, k+4, k+6, k+8, k+10 are semiprimes.at n=17A092128
• Numbers which do not reach zero under either of the iterations: x -> floor(sqrt(x)) * (x - floor(sqrt(x))^2) or y -> ceiling(sqrt(y)) * (ceiling(sqrt(y))^2 - y).at n=37A219963
• Number of length n+3 0..3 arrays with no four elements in a row with pattern abba (with a!=b) and new values 0..3 introduced in 0..3 order.at n=6A243384
• T(n,k)=Number of length n+3 0..k arrays with no four elements in a row with pattern abba (with a!=b) and new values 0..k introduced in 0..k order.at n=42A243389
• Numbers n such that A277118(n) = 17.at n=12A277119
• Numerators of the convergents given by treating A391217 as continued fraction coefficients after the leading 0.at n=12A392258