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A155661
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a(n) = 10^n-7^n+1.
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13
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1, 4, 52, 658, 7600, 83194, 882352, 9176458, 94235200, 959646394, 9717524752, 98022673258, 986158712800, 9903110989594, 99321776927152, 995252438490058, 9966767069430400, 99767369486012794, 998371586402089552
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OFFSET
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0,2
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LINKS
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FORMULA
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G.f.: 1/(1-10*x)-1/(1-7*x)+1/(1-x).
E.g.f.: e^(10*x)-e^(7*x)+e^x.
a(0)=1, a(1)=4, a(2)=52, a(n)=18*a(n-1)-87*a(n-2)+70*a(n-3). - Harvey P. Dale, May 05 2011]
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MATHEMATICA
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Table[10^n-7^n+1, {n, 0, 20}] (* or *) LinearRecurrence[{18, -87, 70}, {1, 4, 52}, 21] (* Harvey P. Dale, May 05 2011 *)
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PROG
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CROSSREFS
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Cf. A155638, A155639, A155640, A155641, A155642, A155643, A155644, A155645, A155646, A155647, A155648, A155649, A155650, A155651, A155652, A155653, A155654, A155655, A155656, A155657, A155658, A155659, A155660.
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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