A111678 a(n+1) = least palindrome not already used that is either a divisor or multiple of a(n) such that the ratios a(n+1)/a(n) are all distinct.

1, 2, 6, 3, 33, 11, 44, 4, 88, 22, 616, 7, 161, 16261, 101, 505, 5, 515, 515515, 55, 5005, 77, 1001, 6006, 66, 2112, 8, 232, 25752, 111, 777, 20202, 666666, 9, 171, 43434, 82177128, 99, 3663, 54945, 333, 15651, 141, 27072, 282, 29892, 212, 25652, 121

Offset

1,2

Links

Table of n, a(n) for n=1..49.

Example

3 is not followed by 9 because 9/3 = 3 = a(3)/a(2).
3 is not followed by 12, 15, 18, 21, 24, 27, or 30 because none of these are palindromes.
88 is not followed by 8 because 8/88 = 1/11 = a(8)/a(7).

Crossrefs

Sequence in context: A304087 A284003 A172031 * A206429 A101819 A177761

Adjacent sequences: A111675 A111676 A111677 * A111679 A111680 A111681

Keyword

base,nonn,easy,less

Author

Amarnath Murthy, Aug 16 2005

Extensions

Edited and extended David Wasserman, Feb 11 2009

Status

approved