A158642 Palindromic numbers which are the product of a number n and its reversal (n written backwards)

0, 1, 4, 9, 121, 252, 484, 10201, 12321, 14641, 20502, 23632, 26962, 40804, 44944, 1002001, 1113111, 1226221, 1234321, 1357531, 2005002, 2126212, 2216122, 2249422, 2347432, 2429242, 4008004, 4229224, 100020001

Offset

0,3

Comments

Apart from 3 which produces 9 (3*3), all the other numbers n which satisfy the definition are formed by digits 0, 1 and 2 only. Subset of A002113.

Every term has an odd number of digits. - Floris van Doorn, Sep 25 2009

Links

Floris P. van Doorn, Table of n, a(n) for n=0,...,10126 (every term with at most 27 digits)

Example

0*0=0; 1*1=1; 2*2=4; 3*3=9; 11*11=121; 12*21=252; 22*22=484; 101*101=10201; 102*201=20502; etc.

Crossrefs

Cf. A002113

Sequence in context: A115676 A115667 A229971 * A131760 A002779 A028817

Adjacent sequences: A158639 A158640 A158641 * A158643 A158644 A158645

Keyword

easy,nonn,base

Author

Paolo P. Lava and Giorgio Balzarotti, Mar 23 2009

Extensions

Corrected by Floris P. van Doorn, Sep 25 2009

Status

approved