194446

Appears in sequences

• Number of multiples of 3 in 0..2^n-1 with an even sum of base-2 digits.at n=20A036557
• Expansion of (1+x*C^4)*C, where C = (1-(1-4*x)^(1/2))/(2*x) is g.f. for Catalan numbers, A000108.at n=10A070859
• Expansion of g.f.: (1-2*x)*(1-4*x+x^2)/((1-x)*(1-3*x)*(1-4*x)).at n=10A087433
• Constant term of the reduction of the polynomial p(n,x)=(1/2)((x+2)^n+(x-2)^n) by x^2->x+2.at n=10A192355