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%I #26 Dec 31 2023 17:55:58
%S 7,27,227,2227,22227,222227,2222227,22222227,222222227,2222222227,
%T 22222222227,222222222227,2222222222227,22222222222227,
%U 222222222222227,2222222222222227,22222222222222227,222222222222222227
%N a(n) = (2*10^n+43)/9.
%C n-1 2's followed by a 7.
%H Markus Tervooren, <a href="http://factordb.com/search.php?query=%282%2A10%5Ex%2B43%29%2F9">Factorizations of (2)w7</a>
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (11,-10).
%F a(n) = 10*a(n-1)-43 with n>1, a(1)=7. - _Vincenzo Librandi_, Dec 05 2010
%F a(n) = a(n-1)+2*10^(n-1) with n>1, a(1)=7. - _Zak Seidov_, Dec 05 2010
%F From _Colin Barker_, Jan 24 2013: (Start)
%F a(n) = 11*a(n-1)-10*a(n-2).
%F G.f.: -x*(50*x-7)/((x-1)*(10*x-1)). (End)
%t Table[FromDigits[PadLeft[{7},n,2]],{n,20}] (* or *) LinearRecurrence[{11,-10},{7,27},20] (* _Harvey P. Dale_, Jan 06 2023 *)
%K easy,nonn
%O 1,1
%A _Ivan Panchenko_, Feb 12 2010
%E More terms from _Vincenzo Librandi_, Feb 24 2010
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