Palindromes n such that 4n + 1 is also a palindrome.

Terms

a(0) =1a(1) =2a(2) =8a(3) =88a(4) =131a(5) =141a(6) =232a(7) =242a(8) =888a(9) =8888a(10) =13031a(11) =13131a(12) =13231a(13) =14041a(14) =14141a(15) =14241a(16) =23032a(17) =23132a(18) =23232a(19) =24042a(20) =24142a(21) =24242a(22) =88888a(23) =888888a(24) =1303031a(25) =1304031a(26) =1313131a(27) =1314131a(28) =1323231a(29) =1324231