1293938646

Appears in sequences

• Number of genus 2 rooted maps with 1 face with n vertices.at n=8A006298
• Denominator of Sum_{i=1..n} 1/(prime(i)*prime(i+1)).at n=8A241190
• a(n) is the number of rooted maps with n edges and 9 faces on an orientable surface of genus 2.at n=0A288089
• a(1) = 1; thereafter a(n) = a(n-1) / lpf(n) if lpf(n) divides a(n-1), otherwise a(n) = a(n-1) * lpf(n), where lpf is the least prime factor function A020639.at n=30A337643