189750626

Appears in sequences

• a(0) = 1, a(1) = 2, a(n) = 4*a(n-1) - a(n-2).at n=15A001075
• Related to Bernoulli numbers.at n=14A002316
• a(2*n) = a(2*n-1) + a(2*n-2), a(2*n+1) = 2*a(2*n) + a(2*n-1); a(0) = a(1) = 1.at n=30A002531
• a(n) = (1 + a(n-1)*a(n-2))/a(n-3), a(0) = a(1) = a(2) = 1.at n=31A005246
• Numerators of continued fraction convergents to sqrt(27).at n=9A041042
• Numerators of continued fraction convergents to sqrt(75).at n=19A041132
• Numerators of continued fraction convergents to sqrt(363).at n=5A041686
• Numerators of continued fraction convergents to sqrt(675).at n=9A042298
• Numbers k such that k^2-1 and k^2 are consecutive powerful numbers.at n=22A060860
• a(n) = 14*a(n-1) - a(n-2); a(0) = a(1) = 2.at n=8A094347
• a(n) = 2702*a(n-1) - a(n-2); a(-1) = a(0) = 26.at n=3A094835
• x such that x^2 - 27*y^2 = 1.at n=5A114052
• Expansion of (1-x)*(2*x^2-4*x+1)/(1-2*x+5*x^2-4*x^3+x^4).at n=28A131039
• a(n) = 16*n^5 - 20*n^3 + 5*n.at n=26A243131
• Denominators of the other-side convergents to sqrt(3).at n=29A259592
• Numerators of the other-side convergents to sqrt(3).at n=28A259593
• Even numbers k such that k^2 - 1 is a powerful number.at n=3A365983