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A131810
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Additive persistence of Catalan numbers.
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1
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0, 0, 0, 0, 1, 1, 1, 2, 1, 2, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 3, 3, 3, 3, 2, 3, 2, 2, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 2, 2, 2, 3, 2, 3, 2, 2, 2, 3, 3, 2, 2, 2, 3, 2, 4, 3, 2, 3
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OFFSET
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0,8
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LINKS
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EXAMPLE
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Catalan number 429 -> 4+2+9=15 -> 1+5=6 thus persistence is 2
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MAPLE
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with(numtheory): with(combinat): P:=proc(n) local a, t; t:=0; a:=(2*n)!/(n!*(n+1)!); while a>9 do t:=t+1; a:=convert(convert(a, base, 10), `+`); od; t;
end: seq(P(i), i=0..10^2);
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CROSSREFS
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KEYWORD
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easy,nonn,base
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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