5242880

Appears in sequences

• a(n) = n*2^(2*n-1).at n=10A002699
• Expansion of (1+x)/(1-4*x).at n=11A003947
• Berstel sequence: a(n+1) = 2*a(n) - 4*a(n-1) + 4*a(n-2).at n=31A007420
• a(n) = 5 * 2^n.at n=20A020714
• Triangle whose (i,j)-th entry is binomial(i,j)*8^(i-j)*8^j.at n=24A038286
• Denominators in the Taylor series for arccosh(x) - log(2*x).at n=9A052469
• a(0)=0, a(1)=1, a(n) = n*2^(n-2) for n >= 2.at n=20A057711
• Numbers k such that k = 2*phi(k) + phi(phi(k)).at n=38A063920
• Expansion of g.f.: (1+x^2)/(1-2*x).at n=22A084215
• a(0)=1, a(1)=5, a(n+2)=4a(n), n>0.at n=21A084568
• a(n) = Sum_{k=0..n} binomial(n+(-1)^k, k).at n=21A087940
• Number of subsets of {1,.., n} containing exactly one prime.at n=28A089821
• Number of subsets of {1,.., n} containing exactly one square.at n=24A089889
• a(n) = the least number which is the average of two consecutive primes and has exactly n prime factors (counted with multiplicity).at n=19A092576
• Expansion of (1+x)^2/(1-4*x^2).at n=22A104721
• Smallest number beginning with 5 and having exactly n prime divisors counted with multiplicity.at n=20A106425
• a(n) is the number of divisors of N, where N = concatenation of n taken n times.at n=44A110758
• Number of ternary Lyndon words of length n with exactly two 1's.at n=18A124720
• a(n) = (n+1)*2^(n*(n+1)).at n=4A128406
• Binomial transform of A124625.at n=20A129952