A006960: Missing the Palindrome
196, 887, 1675, 7436, 13783, 52514, 94039, 187088, 1067869, ...

Let's start with any easy sequence. 1, 2, 4, 8, 16, 77, 154, ... Why the jump from 16 to 77 when everything else is just multiplied by 2? Because this sequence is not A[n+1]=A[n]+A[n], it's actually A[n+1]=A[n]+ReverseTheDigitsOf(A[n]). Here are some other instances of it, starting with different initial values:

• 1, 2, 4, 8, 16, 77, 154, ...
• 3, 6, 12, 33, 66, 132, 363, ...
• 5, 10, 11, 22, 44, 88, 176, ...
• 7, 14, 55, 110, 121, 242, 484, ...
• 9, 18, 99, 198, 1089, 10890, 20691, ...
• 13, 44, 88, 176, 847, 1595, 7546, ...

Notice that in each, the sequence quickly hits a palindromic number - a number x such that x=ReverseTheDigitsOf(x). Actually most of them start with a palindomic number since every single digit number is palindromic. Say you have a number with N digits (we'll let N=2k). Once you know the first k digits, you know constr