a(n) = floor(2nd elementary symmetric function of Sum_{j=1..k} 1/j, k = 1,2,...,n).

Terms

a(0) =1a(1) =6a(2) =15a(3) =29a(4) =51a(5) =79a(6) =117a(7) =163a(8) =220a(9) =287a(10) =365a(11) =455a(12) =558a(13) =673a(14) =802a(15) =945a(16) =1102a(17) =1273a(18) =1460a(19) =1663a(20) =1881a(21) =2116a(22) =2368a(23) =2636a(24) =2922a(25) =3226a(26) =3548a(27) =3888a(28) =4247a(29) =4625