Heptagonal numbers (A000566) in which parity of digits alternates.

Terms

a(0) =1a(1) =7a(2) =18a(3) =34a(4) =81a(5) =189a(6) =616a(7) =783a(8) =874a(9) =3010a(10) =4141a(11) =4347a(12) =5452a(13) =6943a(14) =8323a(15) =12145a(16) =14707a(17) =18361a(18) =52345a(19) =69472a(20) =74563a(21) =78943a(22) =96727a(23) =129618a(24) =147258a(25) =163456a(26) =214183a(27) =232105a(28) =250747a(29) =258727