133875

Appears in sequences

• a(n) = 225*(n-1)*(n-2)/2.at n=33A027470
• Numbers which in at least two ways are the product of two distinct numbers with the same digits (leading zeros are forbidden).at n=3A077760
• Expansion of g.f.: x^4/((1+2*x) * (1-2*x+x^2+2*x^3)).at n=21A123957
• Number of 4-cycles in the n X n rook graph.at n=14A288962
• Number of multisets of exactly six nonempty words with a total of n letters over n-ary alphabet such that within each prefix of a word every letter of the alphabet is at least as frequent as the subsequent alphabet letter.at n=10A294008
• Number of achiral colorings of the 30 triangular faces of a regular icosahedron or the 30 vertices of a regular dodecahedron using n or fewer colors.at n=2A337960