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A099187
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Let D(n) = n*(9*n^2-9*n+2)/2 then a(k+1) = D(a(k)) and a(0) = 1.
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1
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OFFSET
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1,2
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LINKS
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FORMULA
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Let D(n) = n*(9*n^2-9*n+2)/2 then a(k+1) = D(a(k)) and a(0) = 1.
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MATHEMATICA
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Dod[n_]:= n*(9*n^2-9*n+2)/2;
a[n_]:= If[n==0, Dod[1], If[n==1, Dod[2], Dod[a[n-1]]]];
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PROG
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(PARI) dod(n) = n*(9*n^2-9*n+2)/2;
a(n) = if (n==0, 1, if (n==1, dod(2), dod(a(n-1)))); \\ Michel Marcus, Dec 14 2015
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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