151316

Appears in sequences

• a(n) = 4*a(n-1) - a(n-2) with a(0) = 0, a(1) = 1.at n=10A001353
• a(n) = 4*a(n-2) - a(n-4) for n > 1, a(n) = n for n = 0, 1.at n=20A002530
• Pisot sequence E(4,15): a(n) = floor(a(n-1)^2/a(n-2)+1/2) for n>1, a(0)=4, a(1)=15.at n=8A010905
• Expansion of (1 + x + x^2)/(1 - 4x^2 + x^4).at n=19A108412
• Triangle A124029 with the (0,0) entry replaced by 4.at n=45A123966
• Center antidiagonal four in a tri-antidiagonal n-th Matrix generated triangular sequence: first element as 4==m[1,1,1].at n=45A124028
• Triangle T(n,k) with the coefficient [x^k] of the characteristic polynomial of the following n X n triangular matrix: 4 on the main diagonal, -1 of the two adjacent subdiagonals, 0 otherwise.at n=45A124029
• Interleave denominators and numerators of convergents to sqrt(3).at n=28A140827
• Numerators b(n) of Pythagorean approximations b(n)/a(n) to sqrt(3).at n=8A195503
• Triangle of coefficients of Chebyshev's S(n,x+4) polynomials (exponents of x in increasing order).at n=45A207823
• a(n) = 512*n^9 - 1024*n^7 + 672*n^5 - 160*n^3 + 10*n.at n=2A242854
• 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=30A249578
• T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with no 2X2 subblock having its maximum diagonal element less than its minimum antidiagonal element.at n=28A250956
• Denominators of the other-side convergents to sqrt(3).at n=18A259592
• Triangle read by rows: T(n,k) is the number of words over alphabet {0,1,2,3} having exactly k occurrences of the string 01, where n>=0 and k>=0.at n=25A261711
• p-INVERT of the positive integers, where p(S) = 1 - 4*S^2.at n=9A290908
• Number of spanning trees in the graph P_10 x P_n.at n=1A334005
• The largest denominator that can be made from n repeated applications of the maps f(x) = x + 1 or g(x) = -1/x, starting from 0.at n=45A350391
• T(n,m) is the denominator of the resistance between two nodes located at the end of a side of length n of a rectangular electric network of n*m quadratic meshes in which all edges are replaced by one-ohm resistors, where T(n,m) is a square array read by descending antidiagonals.at n=36A357116
• T(n,k) are the values of a variant of the Chebyshev polynomials P(n,x) of order n evaluated at x = k, where T(n,k), n >= 0, k <= n is a triangle read by rows. P(0,x) = 1, P(1,x) = x, P(n,x) = x*P(n-1,x) - P(n-2,x).at n=49A357892