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A135403
a(n) = 1 + 111110*n.
1
1, 111111, 222221, 333331, 444441, 555551, 666661, 777771, 888881, 999991, 1111101, 1222211, 1333321, 1444431, 1555541, 1666651, 1777761, 1888871, 1999981, 2111091, 2222201, 2333311, 2444421, 2555531, 2666641, 2777751, 2888861, 2999971, 3111081, 3222191
OFFSET
0,2
FORMULA
From G. C. Greubel, Oct 12 2016: (Start)
G.f.: (1 + 111109*x)/(1 - x)^2.
E.g.f.: (1 + 111110*x)*exp(x).
a(n) = 2*a(n-1) - a(n-2). (End)
MATHEMATICA
1+111110*Range[0, 30] (* Harvey P. Dale, Sep 21 2012 *)
LinearRecurrence[{2, -1}, {1, 111111}, 25] (* G. C. Greubel, Oct 12 2016 *)
CROSSREFS
Sequence in context: A223110 A094325 A171725 * A154549 A038448 A097077
KEYWORD
nonn,easy
AUTHOR
Dohong Kim 20710847 (upossss(AT)naver.com), Dec 11 2007
EXTENSIONS
a(12) and a(13) corrected by T. D. Noe, Mar 14 2008
More terms from Harvey P. Dale, Sep 21 2012
STATUS
approved