-351

Appears in sequences

• Glaisher's function V(n).at n=17A002611
• Percolation series for hexagonal lattice.at n=13A006803
• Expansion of Product_{k>=1} (1 - x^k)^9.at n=38A010817
• a(n) = -(1/2)*(n+2)*(n^2 - 6*n - 1).at n=11A028494
• Expansion of g.f. Product_{n>=1} (1-x^n)*(1-x^(5*n))/(1-x^(3*n))^2.at n=32A054274
• a(1)=a(2)=1, a(n+2)=a(n+1)+a(n)+(-2)^n.at n=10A073845
• Dirichlet inverse of the gcd-sum function (A018804).at n=69A101035
• Binomial transform of Moebius sequence.at n=11A104688
• Triangle T that satisfies the matrix products: C*[T^-1]*C = T and T*[C^-1]*T = C, where C is Pascal's triangle.at n=41A118801
• Triangle T that satisfies the matrix products: C*[T^-1]*C = T and T*[C^-1]*T = C, where C is Pascal's triangle.at n=31A118801
• Triangle read by rows: a(n,m)=(2*n-1)*(n-m)*(n+m+1)/2, where n is the column and m the row index.at n=52A120476
• Matrix inverse of triangle A122177, where A122177(n,k) = C( k*(k+1)/2 + n-k + 2, n-k) for n>=k>=0.at n=15A121437
• Riordan array (1/(1+x+x^2),x/(1+x)^2).at n=39A122917
• For all n >= 2, Sum_{2<=k<=n, gcd(k,n)>1} a(k) = n. a(1)=1.at n=47A124386
• Expansion of (1+x)/(1-x^2+x^3).at n=29A124745
• Expansion of (b(q) / b(q^2))^3 in powers of q where b() is a cubic AGM theta function.at n=5A128642
• a(n) = (-1)^n * Sum_{i=1..floor(n/2)} i * floor(n/(n-i)).at n=53A131119
• Row sums of triangle A132898.at n=17A132899
• a(n) = 13 + 12*n - n^2.at n=26A136316
• Numerators of upper right triangle of a(i,j) = Integral_{x=i..i+1} Sum_{k=0..j} A048994(j,k)*x^k.at n=29A140825