28531

Appears in sequences

• Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 51 ones.at n=1A031819
• Expansion of x/( 1+x-x^2-x^4-x^5-x^6-x^7+x^9+x^10 ).at n=20A142155
• a(n) = (4*n^3-3*n^2+5*n-3)/3.at n=27A177342
• a(n) = Sum_{i=1..n, j=1..n, gcd(i,j)=1} i.at n=44A333297