314928

Appears in sequences

• Number of invertible 2 X 2 matrices mod n.at n=26A000252
• Next-to-last diagonal of A024462.at n=11A038765
• "Second factorials": Product_{k=1..n} k^(k^2).at n=2A051675
• Write n in decimal, omit 0's, replace the k-th digit d[k] with the k-th prime, raised to d[k]-th power and multiply.at n=49A061509
• Numbers k that, when expressed in base 6 and then interpreted in base 9, give a multiple of k.at n=23A062939
• Numbers n such that n=phi(n)*core(n) where phi(x) is the Euler totient function and core(x) the squarefree part of x (the smallest integer such that x*core(x) is a square).at n=33A069185
• Numbers k such that Sum_i ( e(i)/p(i) ) is an integer, where the prime factorization of k is Product_i ( p(i)^e(i) ).at n=29A072873
• Increasing gaps between 3-smooth numbers (upper end).at n=40A084790
• Numbers of the form (p1^(p1^2))*(p2^(p2^2))*...*(pk^(pk^2)) where p1,p2,..,pk are distinct primes. (In other words: in the prime factorization of any term, the exponent of p is either 0 or p^2 for all prime p).at n=2A089232
• n*phi(n)*phi(phi(n)) is a fourth power.at n=8A116003
• Number of isolated 0's in all ternary words of length n on {0,1,2}.at n=10A120926
• 3-smooth numbers 2^i*3^j where i and j are regular 3-smooth numbers.at n=45A120942
• a(n) = (n^3 - n^2)*9^n.at n=3A128992
• a(n) = 3*a(n-1) if n is odd, otherwise 6*a(n-1).at n=9A130505
• Number of labeled directed trees with n nodes.at n=5A136719
• Triangle T(n, k) = [x^k] p(n, x), where p(n, x) = (1/n)*(1-x)^(2*n) * Sum_{j >= 0} binomial(n+j-1, j) * j^n * x^(j-1).at n=38A152260
• Number of permutations of 8 indistinguishable copies of 1..n arranged in a circle with exactly 1 local maximum.at n=4A159739
• Numbers k that have measure of smoothness J larger than 7, where J = log(k)/log(rad(k)) and rad(k) is the product of the distinct prime divisors of k (A007947).at n=16A172422
• Numbers k such that tau(tau(k)) = rad(k).at n=37A173746
• One quarter the number of nX3 1..4 arrays with no two neighbors of any element equal to each other.at n=8A183355