253706790

Appears in sequences

• Second differences of Catalan numbers A000108.at n=16A026012
• a(n) = T(n, [n/2]), where T is the array defined in A026009.at n=32A026021
• Expansion of (1+x^3*C^4)*C, where C = (1-(1-4*x)^(1/2))/(2*x) is g.f. for Catalan numbers, A000108.at n=17A071738