21869

Appears in sequences

• Numbers having four 5's in base 8.at n=7A043444
• a(n) = sum of numbers without digit 1 and with product of digits = n-th 7-smooth number.at n=24A130975
• a(n) = 729*n - 1.at n=29A158395
• a(n) = 30*n^2 - 1.at n=26A158560
• Numerator of A166100(A166101(n))/A166102(n).at n=36A166272
• a(n) = n^3 - 3n^2 + 3.at n=29A177058
• Start with 1 and 5, then repeatedly adjoin the smallest number that is greater than the last term and not equal to the sum of a subset of the existing terms.at n=17A188793
• a(n) = 10*3^n - 1.at n=7A198645
• The Wiener index of the graph obtained by applying Mycielski's construction to a benzenoid consisting of a linear chain of n hexagons.at n=14A228597
• Array A read by upward antidiagonals in which the entry in row n and column k is defined by A(n,k) = (3/2)*(3^k - 1) + A265159(n,k), n,k >= 1.at n=33A265161
• Number of separable partitions of n in which the number of distinct (repeatable) parts <= 6.at n=38A325715