211680

Appears in sequences

• Lah numbers: a(n) = n! * binomial(n-1, 4)/5!.at n=4A001777
• Number of labeled connected graphs with n nodes and 2 cutpoints.at n=3A013924
• a(n) = n^2*(n+1)*(n+2)!/48.at n=4A037959
• E.g.f. (1-x)/(1-x-2x^2).at n=7A052598
• Expansion of e.g.f. x*(1 - 2*x - sqrt(1-4*x))/2.at n=7A052711
• Expansion of e.g.f. x*(1 - sqrt(1 - 4*x))/2.at n=7A052717
• Number of n-bead necklaces with exactly six different colored beads.at n=8A056286
• Number of primitive (period n) n-bead necklaces with exactly six different colored beads.at n=8A056291
• Coefficient triangle of generalized Laguerre polynomials (a=1).at n=40A066667
• Triangle read by rows: T(n,k) is the number of n-bead necklaces with exactly k different colored beads.at n=41A087854
• Triangular array A066667 or A008297 unsigned and transposed.at n=40A089231
• Number of permutations with self-conjugate cycle types.at n=9A090694
• Permanent of the n X n (0,1)-matrices with ij-th entry equal to zero iff (i=1,j=1),(i=1,j=n),(i=n,j=1) and (i=n,j=n).at n=6A098916
• Triangle read by rows: T(n,k) = binomial(n,k)*(n-1)!/(k-1)!.at n=40A105278
• The matrix inverse of the unsigned Lah numbers A271703.at n=50A111596
• Denominators of expansion for Debye function for n=1: D(1,x).at n=6A120083
• Number of transitive PSL_2(ZZ) actions on a finite dotted and labeled set of size n.at n=6A121356
• Amicable triples. Sequence gives sigma values: A125490(n) + A125491(n) + A125492(n).at n=12A137231
• A triangular sequence from umbral calculus expansion of _Simon Plouffe_'s rational polynomial for A002890: p(x,t) = exp(x*t)*(1 - 6*t + 9*t^2 - 4*t^3 + t^4)/(4*t - 1)/(2*t - 1).at n=49A137514
• Triangle read by rows, based on the two-variable g.f. exp(x*t)*(x*(1 - 2*exp(x)) - 2*exp(x))/(1 - exp(t)) (the first of two parts).at n=47A138133