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A215146
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a(n) = 21*n + 1.
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3
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1, 22, 43, 64, 85, 106, 127, 148, 169, 190, 211, 232, 253, 274, 295, 316, 337, 358, 379, 400, 421, 442, 463, 484, 505, 526, 547, 568, 589, 610, 631, 652, 673, 694, 715, 736, 757, 778, 799, 820, 841, 862, 883, 904, 925, 946, 967, 988
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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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a(n) = 2*a(n-1) - a(n-2).
G.f.: (1+20*x)/(1-x)^2.
E.g.f.: (21*x + 1)*exp(x). (End)
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MATHEMATICA
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Range[1, 1000, 21]
LinearRecurrence[{2, -1}, {1, 22}, 50] (* G. C. Greubel, Apr 19 2018 *)
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PROG
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(PARI) for(n=0, 50, print1(21*n + 1, ", ")) \\ G. C. Greubel, Apr 19 2018
(Magma) I:=[1, 22]; [n le 2 select I[n] else 2*Self(n-1) - Self(n-2): n in [1..30]]; // G. C. Greubel, Apr 19 2018
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CROSSREFS
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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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