Pentagonal numbers written backwards.

Terms

a(0) =0a(1) =1a(2) =5a(3) =21a(4) =22a(5) =53a(6) =15a(7) =7a(8) =29a(9) =711a(10) =541a(11) =671a(12) =12a(13) =742a(14) =782a(15) =33a(16) =673a(17) =524a(18) =774a(19) =235a(20) =95a(21) =156a(22) =517a(23) =287a(24) =258a(25) =529a(26) =1001a(27) =801a(28) =2611a(29) =7421