564719

Appears in sequences

• a(n) = 4*a(n-1) - a(n-2) with a(0) = 0, a(1) = 1.at n=11A001353
• a(n) = 4*a(n-2) - a(n-4) for n > 1, a(n) = n for n = 0, 1.at n=22A002530
• 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=9A010905
• Bisection of A001353. Indices of square numbers which are also octagonal.at n=5A028230
• Expansion of (1 + x + x^2)/(1 - 4x^2 + x^4).at n=21A108412
• a(n) = - 4*a(n-2) - a(n-4), a(0) = 1, a(1) = -4, a(2) = -6, a(3) = 15.at n=19A109731
• a(2*n) = A028230(n), a(2*n+1) = -A067900(n+1).at n=10A110294
• a(0) = 1, a(1) = -4, a(n) = -4*a(n-1) - a(n-2) for n > 1.at n=10A125905
• Interleave denominators and numerators of convergents to sqrt(3).at n=31A140827
• Denominators of continued fraction convergents to sqrt(3)/2.at n=11A144536
• Numerators b(n) of Pythagorean approximations b(n)/a(n) to sqrt(3).at n=9A195503
• 1024*n^10 - 2304*n^8 + 1792*n^6 - 560*n^4 + 60*n^2 - 1.at n=2A243130
• 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=33A249578
• Denominators of the other-side convergents to sqrt(3).at n=20A259592
• 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=30A261711
• Denominator of Kirchhoff index of ladder graph L_n.at n=10A265031
• Squarefree composite numbers n such that p^2 - 1 divides n^2 - 1 for every prime p dividing n.at n=4A287119
• a(n) = numerator(r(n)) where r(n) = (((1/2)*(sqrt(3) + 1))^n - ((1/2)*(sqrt(3) - 1))^n * cos(Pi*n))/sqrt(3).at n=22A305491
• Composite squarefree numbers k such that k^2-1 is divisible by p-1 and p+1, where p are all the prime factors of k.at n=14A306685
• Primitive part of A001353(n).at n=10A306825