Icosagonal numbers for which the sum of the digits is also an icosagonal number.

Terms

a(0) =0a(1) =1a(2) =7337a(3) =12692a(4) =19505a(5) =37505a(6) =61337a(7) =75440a(8) =146432a(9) =240752a(10) =326801a(11) =358400a(12) =620417a(13) =708401a(14) =802217a(15) =851312a(16) =1007345a(17) =1062272a(18) =1176500a(19) =1235801a(20) =1422452a(21) =1622225a(22) =1835120a(23) =1909001a(24) =2061137a(25) =2219105a(26) =2300276a(27) =2728001a(28) =4010672a(29) =4803401