270600

Appears in sequences

• a(n) = (1/3)*(n^2 + 2*n + 3)*(n+1)^2.at n=29A014820
• Write cosec x = 1/x + Sum e_n x^(2n-1)/(2n-1)!; sequence gives denominators of e_n.at n=19A036283
• Number of cases in which the first player is killed in a Russian roulette game where 5 players use a gun with n chambers and the number of bullets can be from 1 to n. Players do not rotate the cylinder after the game starts.at n=18A119610
• Third-order spt function.at n=19A221141
• a(n) = n * A002445(n).at n=20A228838
• a(n) = Sum_{0<=i<j<=n}L(i)*L(j), where L(k)=A000032(k) is the k-th Lucas number.at n=12A242300
• Coefficients in q-expansion of (E_4^2 - E_2*E_6)/1008, where E_2, E_4, E_6 are the Eisenstein series shown in A006352, A004009, A013973, respectively.at n=8A282050
• For successive terms of A002202, totient values t, lcm({x: phi(x)=t})/gcd({x: phi(x)=t}).at n=16A317013
• a(n) = GCD({(2*n-k)*T(n,k)+(k+1)*T(n,k+1), k=0..n}), where T(n,k) stands for A214406 (the second-order Eulerian numbers of type B).at n=39A339100
• a(n) = denominator(4^(n + 1)*zeta(-n, 1/4)).at n=39A344918
• Expansion of 1/((1 - 2*x)*(1 + x + x^2 + x^3 + x^4)).at n=19A349842
• Expansion of e.g.f. (1/2)*(x^2*exp(x))*(sinh(x))^2.at n=11A373134