21948

Appears in sequences

• n^3*a(n) is the number of circles in complex projective plane tangent to three smooth curves of degree n in general position.at n=26A030653
• a(n) = -a(n-1) - a(n-2) + a(n-3) - a(n-5).at n=29A089134
• (a(2n+1)+a(2n))^2 = a(2n+1) a(2n) (concatenated, not multiplied).at n=37A112268
• a(n) = floor(1/{(10+n^4)^(1/4)}), where {}=fractional part.at n=37A184634
• Left part of the square of the n-th Kaprekar number.at n=25A194218
• Nonnegative values x of solutions (x, y) to the Diophantine equation x^2 + (x+84847)^2 = y^2.at n=15A201917
• Number of -2..2 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 or five distinct values for every i,j,k<=n.at n=11A211569
• Number of ordered triples (w,x,y) with all terms in {-n,...-1,1,...,n} and w+x+y>1.at n=18A211613
• Number of idempotent 4X4 0..n matrices of rank 3.at n=12A224335
• Sum of numbers in the n-th antidiagonal of the reciprocity array of 3.at n=44A259583
• Numbers x such that there exist three integers 0<x<=y, z>0 and w>0 such that sigma(x)^3 = sigma(y)^3 = x^3 + y^3 + z^3 + w^3.at n=32A385397