4718592
domain: N
Appears in sequences
- a(n) = 9*2^n.at n=19A005010
- Theta series of D*_18 lattice.at n=13A022071
- a(n) = n*2^n.at n=18A036289
- a(n) = n*omega(n)^n where omega(n) is the number of distinct prime divisors of n.at n=17A061340
- Reciprocal of n terminates with an infinite repetition of digit 5. Multiples of 10 are omitted.at n=4A064564
- Numbers n such that A017666(n)=phi(n).at n=25A069058
- Let M_n be the n X n matrix m(i,j) = min(prime(i), prime(j)); then a(n) = det(M_n).at n=14A070323
- a(1)=1, then a(n)=3*a(n-1) if n is already in the sequence, a(n)=2*a(n-1) otherwise.at n=21A079352
- Let b(n) equal the product of the exponents in the prime factorization of n. Then a(n) gives the least k such that b(k) = n.at n=37A085629
- Number of subsets of {1,.., n} containing exactly one prime.at n=27A089821
- Number of subsets of {1,.., n} containing exactly two primes.at n=25A089822
- Inverse binomial transform of n*Pell(n).at n=36A093968
- a(n) = number of distinct solutions to equations 1 +- x +- x^2 +- ... +- x^n = 0 over the complex numbers.at n=18A096195
- Expansion of (1 - 4*x + 6*x^2)/(1 - 2*x)^2.at n=19A097064
- a(n) = -2*a(n-1) + 4*a(n-3), with a(0) = 1, a(1) = a(2) = 0.at n=25A099212
- Smallest number beginning with 4 and having exactly n prime divisors counted with multiplicity.at n=20A106424
- a(n) is the number of divisors of the concatenation of 1089 with itself n times.at n=20A110752
- a(n) = 4^n * n*(n+1).at n=8A116144
- Third smallest number with exactly n prime factors.at n=20A116453
- a(n) = 2^(n-1)*A047240(n).at n=18A128205