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A099137
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Iterated pentagonal numbers starting with 2.
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1
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OFFSET
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0,1
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LINKS
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FORMULA
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Let P(n) = n*(3*n-1)/2, a(1) = 2 and a(n) = P(a(n-1)) for n >= 2.
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PROG
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(PARI) a(n)=if(n==1, 2, a(n-1)*(3*a(n-1)-1)/2); \\ Joerg Arndt, Mar 05 2023
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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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EXTENSIONS
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STATUS
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approved
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