185220

Appears in sequences

• Triangle of coefficients in expansion of (3+7x)^n.at n=24A013624
• Numbers k such that the set of prime divisors of k is equal to the set of prime divisors of sigma(k).at n=26A027598
• Triangle whose (i,j)-th entry is binomial(i,j)*7^(i-j)*3^j.at n=24A038269
• Numbers n such that n*sigma(n) is a perfect square.at n=25A069070
• a(n) = n^4 - n^3.at n=21A085537
• a(n) = n*(n + 1)^3.at n=20A085540
• Triangle T(n, k) = (n+2)*c(n+2)*f(n+2)/(f(n-k+1)*f(k+1)) where f(n) = c(n)/(n*c(n-1)), c(n) = (n-3)! for n>2 and 1 otherwise, read by rows.at n=38A171830
• Triangle T(n, k) = (n+2)*c(n+2)*f(n+2)/(f(n-k+1)*f(k+1)) where f(n) = c(n)/(n*c(n-1)), c(n) = (n-3)! for n>2 and 1 otherwise, read by rows.at n=42A171830
• Numbers with prime factorization pq^2r^3s^3.at n=25A190320
• Coefficient triangle of the modified Hermite-Bell polynomials for power -2.at n=35A215269
• Sum of even integers <= n times the sum of odd integers <= n.at n=41A330520
• Numbers k such that the squarefree kernel of sigma(k) is equal to the squarefree kernel of 2*k.at n=27A332208
• The number of regions inside a concave circular triangle formed by the straight line segments mutually connecting all vertices and all points that divide the sides into n equal parts.at n=25A340685
• Irregular triangular array read by rows: T(n,k) is the number of compatible pairs (f,g) of functions from [n] into [n] such that the integer partition induced by f and g is the k-th partition in the canonical (reverse lexicographic) ordering of the partitions, n>=0, 1<=k<=A000041(n).at n=33A390121