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

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A116226 n times n+2 gives the concatenation of two numbers m and m-9. 5
4622, 5377, 7980, 34952, 46865, 53134, 65047, 7056186, 9783459, 43176670, 56823329, 97999800, 447255476452, 552744523547, 755424659534, 799319866013, 997999998000, 4297663349523, 5702336650476, 6971253996227 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Robert Israel, Table of n, a(n) for n = 1..1122

EXAMPLE

97999800 * 97999802 = 96039609//96039600, where // denotes

concatenation.

MAPLE

A:= NULL: count:= 0:

for d from 2 to 40 do

  R:= [msolve(x^2=-8, 10^d+1)];

  T:= sort(select(t -> t*(t+2) mod 10^d >= 10^(d-1), map(t -> subs(t, x-1), R)));

  count:= count+nops(T);

  A:= A, op(T);

od:

A; # Robert Israel, Jan 04 2021

CROSSREFS

Cf. A116095, A116225, A116227, A116233.

Sequence in context: A237634 A051649 A140175 * A115446 A254850 A139410

Adjacent sequences:  A116223 A116224 A116225 * A116227 A116228 A116229

KEYWORD

nonn,base

AUTHOR

Giovanni Resta, Feb 06 2006

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 December 1 02:46 EST 2021. Contains 349426 sequences. (Running on oeis4.)