1180980

Appears in sequences

• Numbers k such that the sum of 2nd, 3rd, 4th and 5th powers of divisors of k are divisible by sum of divisors of k.at n=29A074632
• Begin with first number 15. Add the digits of the first number to give the second; the first number multiplied by the second gives the third. The third number becomes the first in a new "set" of three.at n=10A111298
• a(n) = 3*a(n-1), with a(1) = 20.at n=10A116530
• Triangle read by rows: T(n,k) is number of hex trees with n edges and k nonroot nodes of outdegree 2.at n=37A126183
• Number of hex trees with n edges and having no nonroot nodes of outdegree 2.at n=12A126184
• a(n) = floor(n*3^(n/2)).at n=19A128443
• a(n) = n*(n-1)*9^n.at n=5A128803
• Row sums of A211230.at n=23A211231
• Triangle read by rows: T(0,0) = 1; T(n,k) = 3*T(n-1,k) - 2*T(n-2,k-1) for k = 0..floor(n/2); T(n,k)=0 for n or k < 0. Triangle of coefficients of Fermat polynomials.at n=44A303941
• Triangle read by rows: T(0,0) = 1; T(n,k) = 3 T(n-1,k) - 2 * T(n-3,k-1) for k = 0..floor(n/3); T(n,k)=0 for n or k < 0.at n=42A317502
• a(n) is the smallest nonnegative integer k where exactly n pairs of positive integers (x, y) exist such that x^2 + 11*y^2 = k.at n=11A374160