737280
domain: N
Appears in sequences
- Product of totient function: a(n) = Product_{k=1..n} phi(k) (cf. A000010).at n=12A001088
- a(n) is the n-th quartic factorial number divided by 4.at n=5A034177
- Triangle whose (i,j)-th entry is binomial(i,j)*8^(i-j)*12^j.at n=17A038290
- Triangle whose (i,j)-th entry is binomial(i,j)*12^(i-j)*8^j.at n=18A038334
- Triangle of coefficients of certain exponential convolution polynomials.at n=15A048786
- E.g.f.: x/(1-4*x).at n=6A052570
- Expansion of (1+3*x+4*x^2)/(1-4*x^2+4*x^4).at n=29A058582
- Composites of form prime-1 containing a record number of prime factors.at n=13A066632
- a(n) = Product_{i=2..n} phi(i)/bigomega(i).at n=13A066988
- Smallest k-almost prime between twin primes (for k >= 2).at n=15A068525
- 17-almost primes (generalization of semiprimes).at n=10A069278
- Number of plane binary trees of size n+3 and contracted height n.at n=13A074092
- Refactorable numbers x, such that quotient x/A000005(x) equals a power of 2.at n=18A078541
- 4th-order non-linear ("factorial") recursion: a(0)=a(1)=a(2)=a(3)=1, a(n) = (n+1)*a(n-4).at n=23A081407
- Number of subsets of {1,.., n} containing no twin prime pairs.at n=20A089827
- a(n) = smallest positive number that occurs exactly n times as a difference between two positive squares.at n=38A094191
- Row sums of triangle A094280.at n=17A094283
- Number of divisors of the n-th superior highly composite number.at n=25A098895
- a(n) = (n^3 - n^2)*4^n.at n=5A128987
- Numbers n = 5*k^2 such that n - 1 and n + 1 are (twin) primes (thus k=6*m).at n=9A154672