54180

Appears in sequences

• Sum of the next n members of the list of twin primes.at n=17A038345
• The binary encoding (as a rooted planar tree) of each rooted planar binary tree. See A057123 for illustration.at n=15A057122
• Expansion of (1-x)^(-1)/(1+2*x+x^2-2*x^3).at n=23A077928
• Numbers k such that 2*k-1, 4*k-1, 6*k-1 and 8*k-1 are primes.at n=27A124487
• Numbers k such that 2*k-1, 4*k-1, 6*k-1, 8*k-1 and 10*k-1 are primes.at n=6A124488
• Sum of third powers of two consecutive primes.at n=9A133534
• a(n) = n^3 + (n+2)^3.at n=29A153976
• Number of reduced words of length n in Coxeter group on 7 generators S_i with relations (S_i)^2 = (S_i S_j)^5 = I.at n=6A163345
• Numbers with prime factorization pqrs^2t^2.at n=33A189989
• a(n) = 4*n*(4*n^2 + 3).at n=15A271636
• Expansion of (1/(1 - x))*Product_{k>=1} (1 - x^(3*k))/(1 - x^k).at n=42A304630
• Coefficients of polynomials related to ordered set partitions. Triangle read by rows, T_{m}(n, k) for m = 2 and 0 <= k <= n.at n=18A326477
• a(n) = Sum_{k=1..n} (-1)^(k+1) * floor(n/k)^3.at n=38A344721
• Numbers k for which sigma(k - x) + sigma(k + x) = 8*k has at least one nonnegative solution.at n=30A384841