543339720

Appears in sequences

• Pell numbers: a(0) = 0, a(1) = 1; for n > 1, a(n) = 2*a(n-1) + a(n-2).at n=24A000129
• a(n) = 6*a(n-1) - a(n-2) for n > 1, a(0)=0 and a(1)=2.at n=12A001542
• Number of 2 X n binary arrays with a path of adjacent 1's from upper left corner to anywhere in right hand column.at n=21A069306
• a(1) = 1, a(2) = 2; a(2*k) = 2*a(2*k-1) - a(2*k-2), a(2*k+1) = 4*a(2*k) - a(2*k-1).at n=23A084068
• Expansion of (3 -4*x -3*x^2)/((1-x^2)*(1-2*x-x^2)); a Pellian-related sequence.at n=23A114647
• Numbers k such that 2*k^2+1 is a perfect power.at n=13A117547
• a(n) = 6*a(n-2) - a(n-4) for n > 4, with a(1)=1, a(2)=0, a(3)=3, a(4)=2.at n=25A126354
• a(2n) = A001542(n+1), a(2n+1) = A038761(n+1); a Pellian-related sequence.at n=22A129345
• A trisection of A000129, the Pell numbers.at n=8A142588
• Numerators b(n) of Pythagorean approximations b(n)/a(n) to sqrt(8).at n=10A195539
• Square roots of [A055872/8]: Their square written in base 8, with some digit appended, is again a square.at n=26A204512
• a(n) = 2*a(n-1) + a(n-2) for n > 2, a(0) = a(1) = 1, a(2) = 2.at n=24A215928
• Practical Pell numbers.at n=7A287679
• Denominators of the best approximations for sqrt(2).at n=34A331101