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%I #9 Jun 17 2017 03:56:10
%S 1,11,111,1111,11111,111111,1110111,11100111,111000111,1110000111,
%T 11100000111,111000000111,1110000000111,11100000000111,
%U 111000000000111,1110000000000111,11100000000000111,111000000000000111
%N Palindromes formed from the reflected decimal expansion of the concatenation of 1, 1, 1 and infinite 0's.
%C a(n) is also A147596(n) written in base 2. [From _Omar E. Pol_, Nov 08 2008]
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (11,-10).
%F a(n) = 111+111*10^(n-3) for n>5. a(n) = 11*a(n-1)-10*a(n-2). G.f.: -x*(10*x^2-1)*(100*x^4+10*x^2+1) / ((x-1)*(10*x-1)). - _Colin Barker_, Sep 15 2013
%e n .... a(n)
%e 1 .... 1
%e 2 .... 11
%e 3 .... 111
%e 4 .... 1111
%e 5 .... 11111
%e 6 .... 111111
%e 7 .... 1110111
%e 8 .... 11100111
%e 9 .... 111000111
%e 10 ... 1110000111
%e 11 ... 11100000111
%e 12 ... 111000000111
%e 13 ... 1110000000111
%o (PARI) Vec(-x*(10*x^2-1)*(100*x^4+10*x^2+1)/((x-1)*(10*x-1)) + O(x^100)) \\ _Colin Barker_, Sep 15 2013
%Y Cf. A000533, A138144.
%Y Cf. A138118, A138119, A138120, A138146, A138721, A138826, A147596. [From _Omar E. Pol_, Nov 08 2008]
%K easy,nonn,base
%O 1,2
%A _Omar E. Pol_, Mar 29 2008
%E Better definition. - _Omar E. Pol_, Nov 16 2008
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