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0, 30, 2970, 291060, 28520940, 2794761090, 273858065910, 26835295698120, 2629585120349880, 257672506498590150, 25249276051741484850, 2474171380564166925180, 242443546019236617182820, 23756993338504624316991210, 2327942903627433946447955790, 228114647562150022127582676240
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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0,2
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COMMENTS
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Numbers that both doubles and triples of triangular numbers.
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LINKS
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FORMULA
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a(n) = 99*a(n-1) - 99*a(n-2) + a(n-3) for n > 2.
G.f.: -30*x/((x - 1)*(x^2 - 98*x + 1)). (End)
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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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