109552575

Appears in sequences

• a(n) = 4*a(n-1) - a(n-2) with a(0) = 0, a(1) = 1.at n=15A001353
• a(n) = 4*a(n-2) - a(n-4) for n > 1, a(n) = n for n = 0, 1.at n=30A002530
• 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=13A010905
• Bisection of A001353. Indices of square numbers which are also octagonal.at n=7A028230
• a(n) = 2702*a(n-1) - a(n-2); a(-1) = -15; a(0) = 15.at n=3A094836
• Expansion of (1 + x + x^2)/(1 - 4x^2 + x^4).at n=29A108412
• a(n) = - 4*a(n-2) - a(n-4), a(0) = 1, a(1) = -4, a(2) = -6, a(3) = 15.at n=27A109731
• a(2*n) = A028230(n), a(2*n+1) = -A067900(n+1).at n=14A110294
• a(0) = 1, a(1) = -4, a(n) = -4*a(n-1) - a(n-2) for n > 1.at n=14A125905
• Interleave denominators and numerators of convergents to sqrt(3).at n=43A140827
• Denominators of continued fraction convergents to sqrt(3)/2.at n=15A144536
• Numerators b(n) of Pythagorean approximations b(n)/a(n) to sqrt(3).at n=13A195503
• Denominators of the other-side convergents to sqrt(3).at n=28A259592
• 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=30A305491