42872

Appears in sequences

• Composite and even n such that phi(n) * sigma(n) is one less than a square.at n=27A015721
• Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 18.at n=23A031696
• a(n) is the total radius of gyration of all self-avoiding polygons of length 2n on the square lattice.at n=4A056621
• a(n) = 529*n^2 + 23.at n=9A158631
• A(x) satisfies A005408(x) = A(x)/A(x^2), A005408 = odd numbers.at n=26A173283
• Number of vertices in regular n-gon after 2 generations of mitosis.at n=20A349967