1372684090domain: NAppears in sequences10th binomial transform of (1,0,1,0,1,......), A059841.at n=9A081192For n even a(n) = a(n-1) + 10*a(n-2), for n odd a(n) = a(n-3) + 10 a(n-2); with a(1) = 0, a(2) = 1.at n=19A161999a(n) = ((n+1)^(n-1) + (n-1)^(n-1))/2 for n>=1.at n=9A195136