A028349 Palindromes of form n^2 + n - 1.

1, 5, 11, 55, 131, 181, 505, 929, 1331, 9119, 10301, 14041, 15251, 106601, 145541, 196691, 1003001, 1284821, 1712171, 9452549, 100030001, 106636601, 112434211, 160111061, 174464471, 924494429, 950828059, 990707099