34426978560domain: NAppears in sequencesConsider the geometric progression 1,1/2,1/4,1/8,1/16,1/32,1/64,... Group the terms such that the n-th group contains n terms like this (1/1),(1/2,1/4),(1/8,1/16,1,32),(1/64,1/128,1/256,1/512),... a(n) = floor(1/s(n)) where s(n) is the sum of the members of the n-th group.at n=8A081972