Triangular numbers with property that digits alternate in parity.

Terms

a(0) =1a(1) =3a(2) =6a(3) =10a(4) =21a(5) =36a(6) =45a(7) =78a(8) =105a(9) =210a(10) =276a(11) =325a(12) =496a(13) =561a(14) =630a(15) =703a(16) =741a(17) =903a(18) =1830a(19) =2145a(20) =2701a(21) =5050a(22) =6105a(23) =6903a(24) =8385a(25) =9870a(26) =10585a(27) =12561a(28) =14365a(29) =18145