login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A158642 Palindromic numbers which are the product of a number n and its reversal (n written backwards) 2
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 (list; graph; refs; listen; history; text; internal format)
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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 31 16:23 EDT 2020. Contains 333151 sequences. (Running on oeis4.)