A071278 Sorted list of numbers b(i)*b(j), 2 < i < j, where b = A002113 = 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 22, 33 ... is a list of the decimal palindromes.

6, 8, 10, 12, 12, 14, 15, 16, 18, 18, 20, 21, 22, 24, 24, 27, 28, 30, 32, 33, 35, 36, 40, 42, 44, 44, 45, 48, 54, 55, 56, 63, 66, 66, 66, 72, 77, 88, 88, 88, 99, 99, 110, 110, 132, 132, 132, 132, 154, 154, 165, 165, 176, 176, 176, 198, 198, 198, 198, 202, 220, 220, 222

Offset

1,1

Comments

Old name was: Palindromes which are nontrivial multiples of 2 distinct palindromes.

Repetitions are allowed. 12 appears twice because it is both 2*6 and 3*4.

Links

Table of n, a(n) for n=1..63.

Example

8 is in the sequence because 8=2*4.

Mathematica

Module[{nn=250, pals}, pals=Select[Range[2, nn], PalindromeQ]; Select[Sort[ Times@@#&/@ Subsets[pals, {2}]], #<=nn&]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, May 27 2018 *)

Crossrefs

Cf. A002113.

Sequence in context: A189082 A171562 A018221 * A079772 A080731 A080257

Adjacent sequences: A071275 A071276 A071277 * A071279 A071280 A071281

Keyword

base,nonn

Author

Amarnath Murthy, Jun 07 2002

Extensions

Corrected and extended by Sascha Kurz, Jan 02 2003

Edited (with corrected definition) by N. J. A. Sloane, May 27 2018

Status

approved