51246

Appears in sequences

• Numbers k such that the three second-degree cyclotomic polynomials x^2 + 1, x^2 - x + 1 and x^2 + x + 1 are simultaneously prime when evaluated at x=k.at n=29A087277
• Numbers k such that k and k^2 use only the digits 1, 2, 4, 5 and 6.at n=57A136988
• a(n) is the number of semi-meanders with n top arches that has no arch of length 1 at the ends of the top arch configuration and no arch of length 1 adjacent to the center of the top arch configuration.at n=13A334615