A Pyramid of Palindromes 12 = 1 112 = 121 1112 = 12321 11112 = 1234321 111112 = 123454321 1111112 = 12345654321 11111112 = 1234567654321 111111112 = 123456787654321 1111111112 = 12345678987654321 December 18, 2006May 28, 2007 | Science & Math