Partial sums of skinny numbers (A061909).

Terms

a(0) =1a(1) =3a(2) =6a(3) =16a(4) =27a(5) =39a(6) =52a(7) =72a(8) =93a(9) =115a(10) =145a(11) =176a(12) =276a(13) =377a(14) =479a(15) =582a(16) =692a(17) =803a(18) =915a(19) =1028a(20) =1148a(21) =1269a(22) =1391a(23) =1521a(24) =1721a(25) =1922a(26) =2124a(27) =2334a(28) =2545a(29) =2757