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A103505
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Denominator in expansion of (1-x)ln(1-x).
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1
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1, 1, 2, 6, 12, 20, 30, 42, 56, 72, 90, 110, 132, 156, 182, 210, 240, 272, 306, 342, 380, 420, 462, 506, 552, 600, 650, 702, 756, 812, 870, 930, 992, 1056, 1122, 1190, 1260, 1332, 1406, 1482, 1560, 1640, 1722, 1806, 1892, 1980, 2070, 2162, 2256, 2352, 2450
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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COMMENTS
| See A002378 for many more comments and references.
Denominators for the sequence with e.g.f. (1-x)ln(1-x). Numerators are given by 1-0^n-2(C(1,n)-C(0,n)). Also denominators for the sequence with e.g.f. (1+x)ln(1+x). This sequence has numerators (-1)^n-0^n+2(C(1,n)-C(0,n)).
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FORMULA
| G.f.: (1-2x+2x^2+2x^3-x^4)/(1-x)^3; a(n)=0^n+C(1, n)-C(0, n)+2C(n, 2).
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MATHEMATICA
| CoefficientList[Series[(1-2x+2x^2+2x^3-x^4)/(1-x)^3, {x, 0, 50}], x] (* or *) Denominator/@CoefficientList[Normal[Series[(1-x)Log[1-x], {x, 0, 50}]], x] (* From Harvey P. Dale, Apr 20 2011 *)
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CROSSREFS
| Cf. A000384. Apart from initial terms, same as A002378.
Sequence in context: A098734 A160942 A160929 * A002378 A005991 A194110
Adjacent sequences: A103502 A103503 A103504 * A103506 A103507 A103508
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KEYWORD
| easy,nonn
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AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Feb 09 2005
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