42837

Appears in sequences

• a(n) = 3*a(n-1) + a(n-2), with a(0)=0, a(1)=1.at n=10A006190
• Pisot sequences E(3,10), P(3,10).at n=8A020704
• Denominators of continued fraction convergents to sqrt(13).at n=15A041019
• Numbers k such that 13*k^2 + 4 is a square.at n=5A075835
• a(n) = 2*a(n-2)+4*a(n-4)+a(n-6), n>11.at n=23A107855
• A skew generalized Pascal triangle.at n=54A112906
• Fixed-k dispersion for Q = 13: array D(g,h) (g, h >= 1), read by ascending antidiagonals.at n=25A120863
• Convolution triangle of A006190.at n=45A132964
• Maximum number of points visible from some point in a cubic n x n x n lattice.at n=36A141227
• Array A(n,k) = n*A(n,k-1) + A(n,k-2) read by upward antidiagonals, starting A(n,0) = 0, A(n,1) = 1.at n=88A172236
• List of quadruples (r,s,t,u): the matrix M = [[4,12,9][2,5,3][1,2,1]] is raised to successive powers, then (r,s,t,u) are the square roots of M[3,1], M[3,3], M[1,1], M[1,3] respectively.at n=40A249579
• Indices where A092243 strictly changes sign.at n=35A269737
• a(n) = 3*a(n-2) + a(n-4), a(0)=a(1)=0, a(2)=1, a(3)=2.at n=20A305889
• Integers m such that sigma(m) + sigma(m+1) + sigma(m+2) - sigma(m+3) <= 0, where sigma is the sum of divisors.at n=7A348698
• Triangular array T(n,k), read by rows: coefficients of strong divisibility sequence of polynomials p(1,x) = 1, p(2,x) = 3 + 2*x, p(n,x) = u*p(n-1,x) + v*p(n-2,x) for n >= 3, where u = p(2,x), v = 1 - 2*x - x^2.at n=45A367300