login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A110397 a(n) = (10^k - n)(10^k + n), where k is the number of digits in n. 1

%I #8 Aug 18 2019 01:44:31

%S 99,96,91,84,75,64,51,36,19,9900,9879,9856,9831,9804,9775,9744,9711,

%T 9676,9639,9600,9559,9516,9471,9424,9375,9324,9271,9216,9159,9100,

%U 9039,8976,8911,8844,8775,8704,8631,8556,8479,8400,8319,8236,8151,8064,7975

%N a(n) = (10^k - n)(10^k + n), where k is the number of digits in n.

%H Harvey P. Dale, <a href="/A110397/b110397.txt">Table of n, a(n) for n = 1..1000</a>

%e a(3)=(10-3)(10+3)=91; a(11)=(100+11)(100-11)=111*89=9879.

%p s:=proc(m) nops(convert(m,base,10)) end: a:=n->(10^(s(n))-n)*(10^(s(n))+n): seq(a(n),n=1..55); # s gives number of digits # _Emeric Deutsch_, Aug 01 2005

%t Table[Times@@(10^IntegerLength[n]+{n,-n}),{n,50}] (* _Harvey P. Dale_, May 31 2015 *)

%K base,easy,nonn

%O 1,1

%A _Amarnath Murthy_, Jul 29 2005

%E More terms from _Emeric Deutsch_, Aug 01 2005

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 28 15:38 EDT 2024. Contains 371254 sequences. (Running on oeis4.)