a(n) = position of n^3 + (n+1)^3 + (n+2)^3 in A003072.

Terms

a(0) =6a(1) =15a(2) =29a(3) =54a(4) =88a(5) =139a(6) =203a(7) =271a(8) =369a(9) =479a(10) =615a(11) =770a(12) =960a(13) =1173a(14) =1415a(15) =1688a(16) =1990a(17) =2337a(18) =2692a(19) =3139a(20) =3585a(21) =4073a(22) =4592a(23) =5171a(24) =5796a(25) =6451a(26) =7198a(27) =7967a(28) =8818a(29) =9697