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%I #50 Feb 08 2024 07:10:19
%S 0,7,77,777,7777,77777,777777,7777777,77777777,777777777,7777777777,
%T 77777777777,777777777777,7777777777777,77777777777777,
%U 777777777777777,7777777777777777,77777777777777777,777777777777777777,7777777777777777777,77777777777777777777,777777777777777777777
%N a(n) = 7*(10^n - 1)/9.
%H Ivan Panchenko, <a href="/A002281/b002281.txt">Table of n, a(n) for n = 0..200</a>
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (11,-10).
%F a(n) = A178634(n) / A002283(n). - _Reinhard Zumkeller_, May 31 2010
%F From _Vincenzo Librandi_, Jul 22 2010: (Start)
%F a(n) = a(n-1)+7*10^(n-1) with n>0, a(0)=0.
%F a(n) = 11*a(n-1)-10*a(n-2) with n>1, a(0)=0, a(1)=7. (End)
%F G.f.: 7*x/((x-1)*(10*x-1)). - _Colin Barker_, Jan 24 2013
%F a(n) = 7*A002275(n). - _Wesley Ivan Hurt_, Mar 24 2015
%F E.g.f.: 7*exp(x)*(exp(9*x) - 1)/9. - _Stefano Spezia_, Sep 13 2023
%p A002281:=n->7*(10^n-1)/9: seq(A002281(n), n=0..30); # _Wesley Ivan Hurt_, Mar 24 2015
%t LinearRecurrence[{11,-10},{0,7},25] (* _Robert G. Wilson v_, Jul 06 2013 *)
%o (Magma) [7*(10^n-1)/9 : n in [0..30]]; // _Wesley Ivan Hurt_, Mar 24 2015
%o (PARI) a(n)=7*(10^n-1)/9 \\ _Charles R Greathouse IV_, Sep 24 2015
%Y Cf. A002275, A002276, A002277, A002278, A002279, A002280, A002282, A178630, A178634.
%K easy,nonn
%O 0,2
%A _N. J. A. Sloane_
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