Number of distinct products ij with 0 <= i < j <= n.

Terms

a(0) =0a(1) =1a(2) =2a(3) =4a(4) =7a(5) =11a(6) =14a(7) =20a(8) =25a(9) =32a(10) =37a(11) =47a(12) =52a(13) =64a(14) =71a(15) =79a(16) =88a(17) =104a(18) =112a(19) =130a(20) =140a(21) =151a(22) =162a(23) =184a(24) =193a(25) =211a(26) =224a(27) =240a(28) =253a(29) =281