[seqfan] Re: correcting A181539
Klaus Brockhaus
klaus-brockhaus at t-online.de
Thu Nov 4 07:39:55 CET 2010
Sequence: A181539
Sender: Klaus Brockhaus
Address:klaus-brockhaus at t-online.de
Date of submission: Nov 01 2010
Description of changes, start:
a(2) through a(4), a(7) through a(11) corrected, comment added, example replaced by
Description of changes, end
%I A181539
! %S A181539 1,49,249,1249,18751,218751,781249,24218751,74218751,1425781249,
! %T A181539 13574218751,163574218751
%N A181539 a(n) = smallest number m such that m^2 == 1 mod 10^n.
! %C A181539 All terms have last digit 1 or 9. Squares of terms are 1, 2401, 62001, 1560001, 351600001, 47852000001, 610350000001, 586547900000001, 5508423000000001, 2032852170000000001, 184259414700000000001, 26756525040000000000001.
! %e A181539 1249^2 = 1560001 == 1 mod 10^4, and there is no smaller m such that m^2 == 1 mod 10^4. Hence a(4) = 1249.
%K A181539 more,nonn,new
%O A181539 1,2
%A A181539 Kevin Batista (kevin762401(AT)yahoo.com), Oct 29 2010
Am 03.11.2010 16:51, schrieb N. J. A. Sloane:
> I see that there are 2 different edited versions
> of this sequence waiting to be processed, from
> both Klaus and Bob (and possibly others).
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