Hexagonal numbers for which the sum of the digits is also a hexagonal number.

Terms

a(0) =0a(1) =1a(2) =6a(3) =15a(4) =231a(5) =276a(6) =780a(7) =861a(8) =1653a(9) =1770a(10) =2850a(11) =3003a(12) =4371a(13) =4560a(14) =5995a(15) =6216a(16) =6441a(17) =11175a(18) =14028a(19) =17205a(20) =17578a(21) =20301a(22) =20706a(23) =24090a(24) =24531a(25) =24976a(26) =28203a(27) =32640a(28) =33153a(29) =36856