60021

Appears in sequences

• Triangle read by rows: T(n,k) is the number of noncrossing trees with n edges in which the maximal number of contiguous border edges starting from the root in both directions is equal to k.at n=47A102595
• a(n) = (8*n+3)*(8*n+7).at n=30A146301
• a(n) = 100*n^2 + 100*n + 21.at n=24A152161
• Decimal representation of the middle column of the "Rule 61" elementary cellular automaton starting with a single ON (black) cell.at n=15A266791