a(n)=T(n,n+3), array T as in A049723.

Terms

a(0) =18a(1) =33a(2) =54a(3) =79a(4) =115a(5) =152a(6) =197a(7) =253a(8) =310a(9) =370a(10) =443a(11) =516a(12) =600a(13) =697a(14) =789a(15) =894a(16) =995a(17) =1115a(18) =1232a(19) =1360a(20) =1497a(21) =1626a(22) =1786a(23) =1931a(24) =2091a(25) =2252a(26) =2421a(27) =2609a(28) =2786a(29) =2982