1073741766domain: NAppears in sequencesLet r(n) be the real positive root of Sum_{k=1..n} x^k = 1, then a(n) = round(1/(r(n) - 1/2)).at n=27A079460Row sums of triangle A132731.at n=29A132732Row sums of triangle A132823.at n=30A132824Number of ways to select 3 or more collinear points from a 4 X n grid.at n=27A355552