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A135617
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a(n) is the initial digit of n-th even perfect number.
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7
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6, 2, 4, 8, 3, 8, 1, 2, 2, 1, 1, 1, 2, 1, 5, 1, 9, 3, 1, 4, 1, 5, 3, 9, 1, 8, 3, 1, 1, 1, 2, 1, 8, 8, 3, 1, 8, 9, 4, 7, 4, 7, 4, 7, 2, 1, 5
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OFFSET
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1,1
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COMMENTS
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a(n) is also the initial digit of n-th perfect number A000396(n) if there are no odd perfect numbers.
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LINKS
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EXAMPLE
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a(5) = 3 because the 5th even perfect number is 33550336 and the initial digit of 33550336 is 3.
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MATHEMATICA
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lst = {* the list of terms in A000043 *}; f[n_] := Block[{pn = (2^n - 1) (2^(n - 1))}, Quotient[pn, 10^Floor[ Log[10, pn]] ]]; f@# & /@ lst (* Robert G. Wilson v, Apr 01 2008 *)
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CROSSREFS
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KEYWORD
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nonn,base,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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