497760

Appears in sequences

• Number of switching networks (see Harrison reference for precise definition).at n=2A000827
• First element r of (-1)sigma sociable triple (r,s,t): s=(-1)sigma(r), t=(-1)sigma(s), r=(-1)sigma(t), where if x=Product p(i)^r(i), then (-1)sigma(x)=Product(-1+(Sum p(i)^s(i), s(i)=1 to r(i))).at n=33A049057
• Number of solutions to x^2 + y^2 + z^2 + t^2 == n (mod 2*n) for x,y,z,t in [0, 2*n).at n=33A229294
• a(n) = Sum_{k=0..floor(2*n/5)} (k+1) * binomial(k,2*n-5*k).at n=47A392268