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A115194
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A sequence related to A000108 (Catalan numbers).
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2
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1, 7, 45, 291, 1917, 12867, 87805, 607747, 4257789, 30140419, 215277565, 1549615107, 11230642173, 81882660867, 600196448253, 4420404117507, 32695452696573, 242766809923587, 1808890431799293, 13521381274681347
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| Also one fourth of third diagonal of triangle A115195, called Y(1,2).
Fourth column (m=3) of triangle A115193, called C(1,2).
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FORMULA
| G.f.: (-1+x + (1-3*x)*c(2*x))/(2*(1+x)*x^2), with the o.g.f. c(x) of A000108 (Catalan).
a(n)= A115193(n+3,3), n>=0.
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CROSSREFS
| Sequence in context: A198629 A190973 A099842 * A062274 A143835 A103719
Adjacent sequences: A115191 A115192 A115193 * A115195 A115196 A115197
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KEYWORD
| nonn,easy
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AUTHOR
| Wolfdieter Lang (wolfdieter.lang_AT_physik_DOT_uni-karlsruhe_DOT_de), Feb 23 2006
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