21231

Appears in sequences

• Divisors of 2^42 - 1.at n=37A003547
• Decimal encoding of the prime factorization of n: concatenation of prime factors and exponents.at n=44A067599
• Numbers m such that [A070080(m), A070081(m), A070082(m)] is a right integer triangle.at n=26A070136
• Numbers k such that [A070080(k), A070081(k), A070082(k)] is a right integer triangle with relatively prime side lengths.at n=9A070137
• Number of multiplicity-free labeled floor diagrams with n nodes.at n=7A180271
• Number of n X 2 arrays of the minimum value of corresponding elements and their horizontal or vertical neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 n X 2 array.at n=22A219589
• a(n) = Sum_{i=0..n} digsum_3(i)^4, where digsum_3(i) = A053735(i).at n=62A231505
• Growth series for affine Coxeter group (or affine Weyl group) D_5.at n=18A266760
• Number of nonequivalent dissections of an n-gon into 3 polygons by nonintersecting diagonals rooted at a cell up to rotation.at n=41A295622
• Square array A(n,k) read by descending antidiagonals where A(n,k) is the k-th solution x to A328248(x) = n-1.at n=60A328250
• Numbers that are the sum of four third powers in six or more ways.at n=30A345148
• Numbers that are the sum of four third powers in exactly six ways.at n=25A345149
• Numbers that can be written as the product of two of its divisors such that the reverse of the binary value of the number equals the concatenation of the binary values of the divisors.at n=4A355973
• a(n) = 2*n^3 - 3*n + 1.at n=22A377663
• Number of winning positions for the next player (a, b, c) where 1 <= a, b, c <= n in "Divisor Nim" (see comments).at n=30A383226
• a(n) is the number of positive integers k for which Sum_{i=1..r} p_i = Sum_{i=1..r} e_i = n, where p_1^e_1*...*p_r^e_r is the canonical prime factorization of k.at n=27A390784