2147483648

Appears in sequences

• Numbers k such that phi(sigma(k)) = k.at n=20A001229
• Successive numerators of Wallis's approximation to Pi/2 (reduced).at n=17A001901
• Generalized Euler phi function (for p=2).at n=31A003473
• a(n) = 2^(2n+1).at n=15A004171
• Numerator of n!!/(n+1)!! (cf. A006882).at n=32A004730
• a(0) = 1; thereafter a(n) = denominator of (n-2)!! / (n-1)!!.at n=33A004731
• Numerator of n!!/(n+3)!!.at n=32A004732
• Least number which is side of n Pythagorean triples.at n=29A006593
• Expansion of e.g.f.: 1/2 + exp(-4*x)/2.at n=16A009117
• Coefficients of expansion of (1-x)/(1-2*x) in powers of x.at n=32A011782
• Number of Barlow packings with group P63/mmc(S) that repeat after 4n layers.at n=31A011946
• a(n) = 2^(3*n+1).at n=10A013730
• a(n) = 2^(4*n + 3).at n=7A013777
• a(n) = 2^(5*n + 1).at n=6A013822
• Expansion of g.f.: 2*x*(1-x)/((1-2*x)*(1-2*x^2)).at n=31A014236
• Least k such that (tau(k^3)+2)/3=n.at n=31A016018
• Least k such that (tau(k^k)+k-1)/k=n.at n=31A016025
• Smallest power of 2 that begins with n.at n=20A018802
• Pisot sequences E(4,8), L(4,8), P(4,8), T(4,8).at n=29A020707
• Theta series of D*_31 lattice.at n=31A022084