A129623 Numbers which are the product of a non-palindrome and its reversal, where leading zeros are not allowed.

252, 403, 574, 736, 765, 976, 1008, 1207, 1300, 1458, 1462, 1612, 1729, 1855, 1944, 2268, 2296, 2430, 2668, 2701, 2944, 3154, 3478, 3627, 3640, 4032, 4275, 4606, 4930, 5092, 5605, 5848, 6624, 6786, 7663, 8722, 20502, 23632, 26962, 30492, 31003, 34222

Offset

0,1

Comments

The smallest square in this sequence is 63504 = 252*252 = 144*441.

Links

Table of n, a(n) for n=0..41.

Example

252 = 12*21

Mathematica

Take[Union[ Transpose[ Select[Table[{n, n* FromDigits[Reverse[IntegerDigits[n]]]}, {n, 1000}], Mod[ #[[1]], 10] != 0 && #[[1]] != FromDigits[Reverse[IntegerDigits[ #[[1]]]]] &]][[2]]], 100]

Crossrefs

Cf. A072443 Nonsquares which are the product of two numbers with the same digits (leading zeros are forbidden). A076750 Squares which are the product of a non-palindrome and its reversal, where leading zeros are not allowed.

Sequence in context: A104396 A207373 A072443 * A062904 A032800 A024749

Adjacent sequences: A129620 A129621 A129622 * A129624 A129625 A129626

Keyword

base,nonn

Author

Tanya Khovanova, May 30 2007

Status

approved