280918

Appears in sequences

• Numbers k such that sopf(k) = (1/2)*(sopf(k+1) + sopf(k-1)), where sopf(x) = sum of the distinct prime factors of x.at n=22A075846
• Number of -3..3 arrays x(i) of n+1 elements i=1..n+1 with set{t,u,v in 0,1}((x[i+t]+x[j+u]+x[k+v])*(-1)^(t+u+v)) having two, four, five, six or eight distinct values for every i,j,k<=n.at n=6A211752
• Expansion of Product_{k>=1} (1 + x^k)^(k^(k-2)).at n=8A321388