41287680

Appears in sequences

• Exponential generating function = (1+2*x)/(1-2*x)^3.at n=7A014479
• a(0) = 1; for n > 0, a(n) = n!*4^n/2.at n=7A051711
• a(0) = 2, a(n) = 2^(n+1)*(n-1)! (n >= 1).at n=9A064378
• Maximal number of divisors of any n-digit number.at n=32A066150
• Products of the digits of e excluding 0.at n=12A084674
• a(n) = Product_{k=1..n} lcm(k,n)/gcd(k,n).at n=7A127553
• Array read by antidiagonals: T(n,k) = (k+1)^n*(n+k)!.at n=39A154120
• Triangle T(n, k) = binomial(n, k)*A000166(n-k)*k^n with T(0, 0) = 1, read by rows.at n=40A156788
• The lower left triangle of the ED2 array A167560.at n=34A167569
• a(0)=4; thereafter a(n)=8*n*(2*n-1)*a(n-1).at n=4A257583
• Denominators in expansion of W(exp(x)) about x=1, where W is the Lambert function.at n=7A274448
• Triangle read by rows. A generalization of unsigned Lah numbers, called L[2,1].at n=37A286724
• A variant of payphone permutations: given a circular booth with n payphones, one of which is already occupied, a(n) is the number ways for n-1 people to choose the payphones in order, where each person chooses an unoccupied payphone such that the closest occupied payphone is as distant as possible, and a payphone adjacent to a single occupied payphone is preferred over a payphone sandwiched between two occupied payphones.at n=17A361294
• Triangle read by rows: n-th row polynomial equals the numerator of the rational function (-1)^n*f(x) * (d/dx)^n (1/f(x)), where f(x) = sqrt(x + x^2).at n=43A368235
• a(n) = pos(M(n)), where M(n) is the n X n matrix with every term = 4, and pos(M(n)) is the positive part of the determinant of M(n); see A380661.at n=6A381724