22071

Appears in sequences

• Icosahedral numbers: a(n) = n*(5*n^2 - 5*n + 2)/2.at n=20A006564
• a(n) = Sum_{k=0..floor(n/5)} C(n-3*k,2*k) * 2^k.at n=22A098577
• Number of (n+1)X(n+1) 0..3 symmetric matrices containing all values 0..3 with every 2X2 subblock having one or two distinct values, and new values 0..3 introduced in lower triangle row major order.at n=3A210815
• Trajectory of 80 under the map n-> A006369(n).at n=46A223084
• Number of partitions of n such that (least part) = (multiplicity of greatest part).at n=39A240180
• G.f. A(x) satisfies: A(x^3*R(x)) = x^4 - x^5 where A(R(x)) = x.at n=10A350434
• a(n) = Sum_{k=1..n} sigma_3(k)^2.at n=4A356536