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

 

Logo

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A177950 Numbers n such that n divides R(n^2), where R(k) is the digit reversal of k. 3
1, 2, 3, 9, 11, 22, 26, 33, 48, 66, 87, 99, 101, 111, 117, 121, 202, 212, 216, 264, 273, 288, 297, 307, 333, 484, 513, 528, 666, 783, 819, 836, 999, 1001, 1111, 1323, 1331, 1452, 1474, 1602, 2002, 2178, 2285, 2622, 2636, 3333, 4884, 4961, 6666, 7161, 7575 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..171(* All terms up to n = 10 million *)

EXAMPLE

273 is in the sequence because 273^2 = 74529 and 273|92547.

MAPLE

with(numtheory):T:=array(1..94):k:=1:for n from 1 to 200000 do: n0:=n^2:l:=length(n0) :s:=0:for m from l by -1 to 1 do:q:=n0:u:=irem(q, 10):v:=iquo(q, 10): n0:=v :s:=s+ u*10^(m-1):od:if irem(s, n)=0 then T[k]:=n:k:=k+1:else fi: od:print(T):

MATHEMATICA

Select[Range[1000], Mod[FromDigits[Reverse[IntegerDigits[ (#)^2 ]]], # ]==0 & ]

Select[Range[8000], Divisible[IntegerReverse[#^2], #]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Dec 12 2016 *)

CROSSREFS

Cf. A177948 A177928

Sequence in context: A271548 A110350 A057569 * A049618 A057292 A098016

Adjacent sequences:  A177947 A177948 A177949 * A177951 A177952 A177953

KEYWORD

nonn,base

AUTHOR

Michel Lagneau, May 15 2010

EXTENSIONS

Edited by Charles R Greathouse IV, Aug 02 2010

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 January 17 09:54 EST 2020. Contains 330949 sequences. (Running on oeis4.)