121635

Appears in sequences

• a(n) = 4*a(n-1) - a(n-2), with a(0) = 0, a(1) = 3.at n=9A005320
• Numerators of continued fraction convergents to sqrt(12).at n=8A041016
• Numerators of continued fraction convergents to sqrt(507).at n=8A041968
• Numerators of coefficients in series expansion of -512*(1+x)^3/(x-8)^3.at n=27A066414
• a(n) = 4*a(n-2) - a(n-4).at n=17A083336
• G.f. A(x) satisfies: 6^n - 1 = Sum_{k=0..n} [x^k]A(x)^n and also satisfies: (6+z)^n - (1+z)^n + z^n = Sum_{k=0..n} [x^k](A(x)+z*x)^n for all z, where [x^k]A(x)^n denotes the coefficient of x^k in A(x)^n.at n=11A100234
• Numerators of principal and intermediate convergents to 3^(1/2).at n=26A143642
• Numerators of the lower principal convergents and the lower intermediate convergents to 3^(1/2).at n=17A143643
• List of triples (r,s,t): the matrix M = [[4,12,9][2,7,6][1,4,4]] is raised to successive powers, then (r,s,t) are the square roots of M[3,1], M[1,1], M[1,3] respectively.at n=29A249578
• Numerators of the other-side convergents to sqrt(3).at n=17A259593
• Let a(0)=1. Then a(n) = sums of consecutive strings of positive integers of length 3*n, starting with the integer 2.at n=30A289721
• The number of links of a qualifying "snake" polyline that connects the midpoints of opposite sides of the n-th regular integer hexagon that allows such a construction.at n=9A356047