23040
domain: N
Appears in sequences
- Number of invertible 2 X 2 matrices mod n.at n=14A000252
- Sorted list of orders of Weyl groups of types A_n, B_n, D_n, E_n, F_4, G_2.at n=16A001217
- Index of (the image of) the modular group Gamma(n) in PSL_2(Z).at n=39A001766
- a(n) = binomial(n,2) * 2^(n-1).at n=10A001815
- a(0) = 1; for n > 0, a(n) = 2^(n-1)*n!.at n=6A002866
- Order of orthogonal group O(n, GF(2)).at n=5A003053
- Theta series of packing P_{10c}.at n=6A004021
- Theta series of {D_10}^{+} lattice.at n=13A004532
- Smallest k such that k*n is a double factorial.at n=27A007919
- Theta series of D_6 lattice.at n=21A008428
- Theta series of direct sum of 2 copies of f.c.c. lattice.at n=31A008663
- Expansion of sin(log(1+x))*log(1+x).at n=9A009458
- Number of reversible strings with n labeled beads of 2 colors.at n=5A032107
- Maximal value of d(x) (the number of divisors of x, A000005) if the binary order (see A029837) of x, the value g(x) = n.at n=49A036451
- Triangle whose (i,j)-th entry is binomial(i,j)*4^(i-j)*6^j.at n=17A038236
- Triangle whose (i,j)-th entry is binomial(i,j)*6^(i-j)*4^j.at n=18A038258
- Unitary-sigma sigma multiply perfect numbers: numbers k such that A061765(k) = m*k for some integer m.at n=37A045795
- Denominator of (1/Pi)*Integral_{0..oo} (sin x / x)^n dx.at n=6A049331
- Triangle read by rows: T(n,k) = number of paths of n upsteps U and n downsteps D that contain k UUDs.at n=31A051288
- Order of group G_{1,n}^{8}.at n=4A051526