Numbers k such that k^2 + k + 4 is a palindrome.

Terms

a(0) =0a(1) =1a(2) =20a(3) =200a(4) =219a(5) =261a(6) =2000a(7) =2234a(8) =2551a(9) =2613a(10) =20000a(11) =20604a(12) =200000a(13) =202885a(14) =205704a(15) =218354a(16) =2000000a(17) =2155139a(18) =2490266a(19) =2620486a(20) =20000000a(21) =25882353a(22) =200000000a(23) =205705704a(24) =2000000000a(25) =2094600194a(26) =20000000000a(27) =20102030400a(28) =20349812814a(29) =21572321960