524325

Appears in sequences

• a(n) = 2^n + 2*n - 1.at n=19A061761
• The floor[n^(3/4)]-perfect numbers, where f-perfect numbers for an arithmetical function f is defined in A066218.at n=33A066363
• Start with Pascal's triangle; form a triangle by sliding down n steps from top on both sides and including the horizontal row, deleting the inner numbers; a(n) = sum of entries on perimeter of triangle.at n=19A081494