49171

Properties

Appears in sequences

• Bessel polynomials y_n(x) (see A001498) evaluated at 2.at n=5A001517
• Numerators of approximations to e.at n=30A006258
• Numerators of convergents to e.at n=13A007676
• Primes p whose period of reciprocal equals (p-1)/11.at n=15A056216
• The next smallest pair of numbers is taken so that a(2n-1)/a(2n) converges to e = exp(1).at n=48A065370
• Square array read by antidiagonals of T(n,k)=(4k-2)*T(n,k-1)+T(n,k-2) with T(n,0)=1 and T(n,1)=n.at n=39A079166
• Greedy fractional multiples of 1/e: a(1)=1, Sum_{n>0} frac(a(n)/e) = 1.at n=10A079940
• Expansion of e.g.f. exp(x*C(x)) = exp((1-sqrt(1-4*x))/2), where C(x) is the g.f. of the Catalan numbers A000108.at n=6A080893
• Primes found among the numerators of the continued fraction rational approximations to e.at n=5A086791
• E.g.f.: exp(x)/(1-x)^6.at n=5A096307
• a(3n) = a(3n-1) + a(3n-2), a(3n+1) = 2n*a(3n) + a(3n-1), a(3n+2) = a(3n+1) + a(3n).at n=15A113873
• Numerators of "Farey fraction" approximations to e.at n=32A119014
• Numerators of the other-side convergents to e.at n=12A259589
• Integers in the interval [e*k - 1/k, e*k + 1/k] for some k > 0 , where e = 2.71828... is Euler's number.at n=18A265741
• Numerators of upper primes-only best approximates (POBAs) to e; see Comments.at n=12A265816
• Numerators of primes-only best approximates (POBAs) to e; see Comments.at n=13A265818
• Triangle read by rows: T(n,m) = Sum_{k=m+1..n} (n-1)!/(k-1)!*binomial(2*n-k-1, n-1)*E(k,m) where E(n,m) is Euler's triangle A173018, T(0,0) = 1, n >= m >= 0.at n=21A316773
• Numerators of a sequence of fractions converging to e.at n=8A340737
• Numbers k such that A361338(k) = 10.at n=25A361349
• a(n) is the n-digit numerator of the fraction h/k with h and k coprime positive integers at which abs(h/k-e) is minimal.at n=4A368620