13 Jan
2020
13 Jan
'20
3:53 p.m.
AW: "10^n + 1 = 100...01 is always a palindrome, and no matter what the last entry K is, a big enough n will avoid carries to produce a palindrome of the form K0...0K." Indeed. More generally, palindromes composed of only the digits zero and one are a great help in advancing the sequence. The fourteen terms at even indices from #166 to #192 are all such: ... 22322, 10111101, 10701, 11100111, 4224, 100010001, 373, 100101001, 383, 101000101, 393, 101010101, 464, 1000000001, 474, 1001001001, 484, 1010000101, 494, 10000000001, 505, 110000011, 515, 110010011, 525, 1000110001, 535, 1100000011, 545, ...