73728
domain: N
Appears in sequences
- Number of invertible 2 X 2 matrices mod n.at n=23A000252
- Hadamard maximal determinant problem: largest determinant of (+1,-1)-matrix of order n.at n=9A003433
- a(n) = 9*2^n.at n=13A005010
- Minimal determinant (negated) of n X n persymmetric matrix with entries {-1,0,+1}.at n=9A034917
- Triangle whose (i,j)-th entry is binomial(i,j)*4^(i-j)*12^j.at n=22A038242
- Triangle whose (i,j)-th entry is binomial(i,j)*12^(i-j)*4^j.at n=26A038330
- a(n) = tau(binomial(2*n,n)), where tau = number of divisors (A000005).at n=40A048784
- Number of divisors of lcm(1..n).at n=40A056793
- Number of divisors of lcm(1..n).at n=41A056793
- Number of divisors of k as k runs through sequence of distinct values of LCM(1,..,n).at n=20A056795
- Expansion of (1+3*x+4*x^2)/(1-4*x^2+4*x^4).at n=23A058582
- a(n) = determinant(P*Q)/n! where P, Q are n X n matrices with P[i,j]=lcm(i,j), Q[i,j]=gcd(i,j).at n=7A060239
- Reciprocal of n terminates with an infinite repetition of digit 5. Multiples of 10 are omitted.at n=3A064564
- Composites of form prime+1 containing a record number of prime factors.at n=11A066617
- Triangle related to generalized Catalan numbers A064340.at n=34A067327
- Denominators of coefficients in J0(i*sqrt(x))^2 power series where J0 denotes the ordinary Bessel function of order 0.at n=4A068110
- Numbers n such that A017666(n)=phi(n).at n=13A069058
- 15-almost primes (generalization of semiprimes).at n=2A069276
- Binary expansion is 1xx100...0 where xx = 00 or 11.at n=26A070876
- a(n) = n*2^(n-6).at n=12A078836