// ========================================================= // OEIS ll oeisA210440() { ll n; rd(n); n = n-2; return 2*n*(n+1)*(n+2)/3; } // ========================================================= // 適当に展開した汚い式 ll solve1() { ll n; rd(n); return 2ll*( (n-1)*(n-1)*(n-2)/2 -( (n-1)+(n-1)*n*(2*n-1)/12-3*(n-1)*n/4) ); } // ========================================================= // TLE解法 ll solve2() { ll n; rd(n); vector v(n*2); REP(i, n) { v[i] = n-i; v[n+i] = n-i; } ll n2 = n*2; ll total = 0; REP(i, n2-2) { REP(j, i+1, n2-1) { REP(k, j+1, n2) { if (((v[i] < v[j] && v[j] > v[k]) || (v[i] > v[j] && v[j] < v[k])) && v[i] != v[k]) { total += 1; } } } } return total; } { int t; rd(t); REP(_, t) wt(oeisA210440()); }