a(n) = floor((Sum_{r=1..n} r)*(Sum_{r=1..n} 1/r)).

Terms

a(0) =1a(1) =4a(2) =11a(3) =20a(4) =34a(5) =51a(6) =72a(7) =97a(8) =127a(9) =161a(10) =199a(11) =242a(12) =289a(13) =341a(14) =398a(15) =459a(16) =526a(17) =597a(18) =674a(19) =755a(20) =842a(21) =933a(22) =1030a(23) =1132a(24) =1240a(25) =1352a(26) =1470a(27) =1594a(28) =1723a(29) =1857