51841

Appears in sequences

• Numerators of continued fraction convergents to sqrt(5).at n=8A001077
• Bruckman-Lucas pseudoprimes: k | (L_k - 1), where k is composite and L_k = Lucas numbers A000032.at n=14A005845
• 3rd Euler polynomial evaluated at x=n! (multiplied by 4).at n=4A020548
• a(n) = 18*a(n-1) - a(n-2).at n=4A023039
• Numerators of continued fraction convergents to sqrt(20).at n=7A041030
• Numerators of continued fraction convergents to sqrt(45).at n=11A041076
• Numerators of continued fraction convergents to sqrt(80).at n=7A041142
• Numerators of continued fraction convergents to sqrt(180).at n=7A041332
• Numerators of continued fraction convergents to sqrt(245).at n=9A041458
• Numerators of continued fraction convergents to sqrt(320).at n=7A041604
• Numerators of continued fraction convergents to sqrt(405).at n=3A041768
• Numerators of continued fraction convergents to sqrt(720).at n=7A042386
• Numerators of continued fraction convergents to sqrt(980).at n=9A042896
• Composite n coprime to 5 such that Fibonacci(n) == Legendre(n,5) (mod n).at n=16A049062
• Expansion of x*(1 + x - 2*x^2) / ( 1 - 4*x^2 - x^4).at n=17A059973
• Numbers k such that the period of the continued fraction for sqrt(5)*k is 2.at n=41A065030
• Composite numbers k such that k divides F(k-1) where F(j) are the Fibonacci numbers.at n=15A069106
• Nonprime numbers k such that (k+1)*Sum_{d|k} 1/(d+1) is an integer.at n=19A069155
• a(1)=1; for n > 2, a(n) is the smallest integer > a(n-1) such that frac(sqrt(5)*a(n)) < frac(sqrt(5)*a(n-1)).at n=14A079497
• Odd Fibonacci pseudoprimes: odd composite numbers k such that either (1) k divides Fibonacci(k-1) if k == +-1 (mod 5) or (2) k divides Fibonacci(k+1) if k == +-2 (mod 5).at n=28A081264