Numbers n for which there are exactly seven k such that n = k + reverse(k).

Terms

a(0) =77a(1) =132a(2) =707a(3) =727a(4) =747a(5) =767a(6) =787a(7) =807a(8) =827a(9) =847a(10) =867a(11) =887a(12) =1212a(13) =1232a(14) =1252a(15) =1272a(16) =1292a(17) =1312a(18) =1332a(19) =1352a(20) =1372a(21) =1392a(22) =1661a(23) =2321a(24) =7007a(25) =8987a(26) =12012a(27) =13992a(28) =16061a(29) =16261