28125

Appears in sequences

• Numbers of the form 3^i*5^j with i, j >= 0.at n=37A003593
• Smallest label f(T) given to a rooted tree T with n nodes in Matula-Goebel labeling.at n=19A005517
• a(n) = (2*n - 5)n^2.at n=25A015240
• Expansion of Product_{m>=1} (1+x^m)^9.at n=8A022574
• Numbers of form 5^i*9^j, with i, j >= 0.at n=20A025624
• Numbers whose prime factors are 3 and 5.at n=21A033849
• Triangle whose (i,j)-th entry is binomial(i,j)*5^(i-j)*9^j.at n=16A038251
• Triangle whose (i,j)-th entry is binomial(i,j)*9^(i-j)*5^j.at n=19A038295
• Odd numbers divisible by exactly 7 primes (counted with multiplicity).at n=29A046320
• A convolution triangle of numbers generalizing Pascal's triangle A007318.at n=29A049326
• n satisfying sigma(n+1) = sigma(n-1).at n=32A055574
• Reciprocal of n terminates with an infinite repetition of digit 5. Multiples of 10 are omitted.at n=2A064564
• Numbers k such that sigma(k-1) divides sigma(k+1).at n=38A067130
• The prime factors of n are also prime factors of the decimal encoding (A067599) of the prime factorization of n.at n=31A067671
• Hypotenuses for which there exist exactly 5 distinct Pythagorean triangles.at n=7A084649
• Least k such that decimal representation of k*n contains only digits 0 and 9.at n=31A096688
• a(n) = n*(n+5)*(50+45*n+n^2)/24.at n=19A101861
• Numbers k such that k * phi(k) is a cube.at n=35A114076
• Enneagonal numbers divisible by 9.at n=20A117796
• Triangle, generated from (3^(n-k) * 5^k) table.at n=33A120027