262528

Appears in sequences

• a(n) = a(1)*a(n-1) + a(2)*a(n-2) + ...+ a(n-1)*a(1) for n >= 5, starting 1,1,1,0.at n=15A025274
• Irregular triangle read by rows: T(n,k) (n>=2, 0<=k<=n) = total number of unbranched k-catapolyheptagons with k pentagons and n-k heptagons.at n=54A323850