1398100

Appears in sequences

• Barlow packings with group R3(bar)m(SO) that repeat after 6n+3 layers.at n=21A011954
• a(n) = a(n-1) + 2*a(n-2) + 2, for n>=3, where a(0)= 1, a(1)= 2, a(2)= 4.at n=20A026644
• a(n) = Sum_{j=1..n} phi(n)^j.at n=9A075490
• Partial sums of Jacobsthal gap sequence.at n=20A080610
• a(n) = (4/3)*(4^n - 1).at n=10A080674
• a(n) = -5*a(n-1) - 4*a(n-2), a(0)=1, a(1)=0.at n=11A084240
• Expansion of x*(1+2*x)/((1+x)*(1-x)*(1-2*x)).at n=20A084639
• Expansion of (1+x-4*x^2) / ((1+x)*(1-4*x^2)).at n=21A087213
• a(1) = 4; then alternately add -4 and multiply by -2.at n=41A096406
• Expansion of (1 - 2*x + 2*x^2)/((1 - x^2)*(1 - 2*x)).at n=21A097072
• Expansion of (1-x+2*x^2)/((1+x)*(1-2*x)).at n=21A097073
• Expansion of (1+3x)/((1-x)(1-4x^2)).at n=19A097164
• Expansion of x^3 / ((x-1)*(2*x-1)*(x^2-x+1)).at n=22A111927
• Expansion of -2*x*(-3-2*x+4*x^2) / ((x-1)*(2*x+1)*(2*x-1)*(1+x)).at n=20A120462
• Second differences of A130624.at n=20A130626
• a(n+3) = 3*(a(n+2) - a(n+1)) + 2*a(n).at n=22A130707
• a(n) = 3a(n-1) - 3a(n-2) + 2a(n-3), a(0) = 3, a(1) = 2, a(2) = 0.at n=22A131370
• a(n)= -3a(n-1) -3a(n-2)-2a(n-3), a(0)=1, a(1)=-2, a(2)=2.at n=22A131562
• a(1)=1, a(n) = a(n-1) + (p-1)*p^(n/2-1) if n is even, else a(n) = a(n-1) + p^((n-1)/2), where p=4.at n=19A133628
• Second differences of Jacobsthal sequence A001045, pairs with even and odd indices swapped.at n=23A140505