129904

Appears in sequences

• a(0) = 1, a(1) = 2, for n > 1, a(n) = 4*a(n-1) - 2*a(n-2).at n=10A003480
• Pisot sequence P(2,7): a(0)=2, a(1)=7, thereafter a(n+1) is the nearest integer to a(n)^2/a(n-1).at n=9A020727
• Duplicate of A020727.at n=9A021000
• a(0)=1; a(1)=2; a(n) = a(n-1) + a(n-2)*(3 - (-1)^n)/2.at n=19A062113
• Expansion of (1+2*x-x^3)/(1-4*x^2+2*x^4).at n=19A217730
• Number of length n+6 0..1 arrays with at most one downstep in every 6 consecutive neighbor pairs.at n=16A255990
• Triangle read by rows: T(n,k) is the number of unlabeled connected graphs with n nodes and packing chromatic number k, 1 <= k <= n.at n=41A363044