22619537

Appears in sequences

• Pell-Lucas numbers: numerators of continued fraction convergents to sqrt(2).at n=20A001333
• a(0) = 1, a(1) = 3; for n > 1, a(n) = 6*a(n-1) - a(n-2).at n=10A001541
• Interleave denominators (A000129) and numerators (A001333) of convergents to sqrt(2).at n=41A002965
• Numerators of continued fraction convergents to sqrt(8).at n=19A041010
• Numerators of continued fraction convergents to sqrt(18).at n=9A041026
• Numerators of continued fraction convergents to sqrt(32).at n=19A041052
• Numerators of continued fraction convergents to sqrt(72).at n=9A041126
• Numerators of continued fraction convergents to sqrt(288).at n=9A041542
• Numerators of continued fraction convergents to sqrt(722).at n=13A042390
• a(n) = a(-n) = 34*a(n-1) - a(n-2), and a(0)=1, a(1)=17.at n=5A056771
• Numbers k such that k^2-1 and k^2 are consecutive powerful numbers.at n=18A060860
• Number of 19 X n binary arrays with a path of adjacent 1's from top row to bottom row.at n=1A069377
• Expansion of (1+x)/(1-2*x-x^2).at n=19A078057
• a(0) = a(1) = 1; thereafter a(2*n+1) = 2*a(2*n) - a(2*n-1), a(2*n) = 4*a(2*n-1) - a(2*n-2).at n=20A079496
• Greedy frac multiples of sqrt(2): a(1)=1, Sum_{n>=0} frac(a(n)*x)=1 at x=sqrt(2).at n=28A079934
• Series ratios converge alternately to sqrt(2) and 1+sqrt(1/2).at n=39A082766
• Logarithmic derivative of the g.f. of A113281.at n=19A113282
• Numerators of "Farey fraction" approximations to sqrt(2).at n=40A119016
• a(n) = -2*a(n-1) + a(n-2) for n>1, a(0)=1, a(1)=-1.at n=20A123335
• 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=20A126354