a(n) = 2^((n-1)*(n+2)/2).A036442a(n) = 2^((n-1)*(n+2)/2).Terms a(0) =1a(1) =4a(2) =32a(3) =512a(4) =16384a(5) =1048576a(6) =134217728a(7) =34359738368External referencesoeis: A036442