503917

Appears in sequences

• a(n) = a(n-1) + 2*a(n-3) with a(0)=a(1)=1, a(2)=3.at n=25A003229
• Expansion of 1/(1-x-2*x^3).at n=26A077949
• Expansion of 1/(1+x+2*x^3).at n=26A077974
• a(n) = A192809(n)/2.at n=10A192811
• Number of nX3 0..1 arrays with every element unequal to 0, 1, 2, 6 or 7 king-move adjacent elements, with upper left element zero.at n=24A305035