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Search: id:A135617
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| A135617 |
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Initial digit of perfect numbers. |
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+0
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
(list; graph; listen)
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OFFSET
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1,1
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LINKS
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O. E. Pol, Determinacion geometrica de los numeros primos y perfectos.
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EXAMPLE
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a(5)=3 because the 5th perfect number A000396(5) 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, (rgwv(AT)rgwv.com), Apr 01 2008
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CROSSREFS
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Cf. A000030, A000396, A077648, A094540.
Sequence in context: A125115 A020831 A156590 this_sequence A019930 A123139 A027599
Adjacent sequences: A135614 A135615 A135616 this_sequence A135618 A135619 A135620
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KEYWORD
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nonn,base
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AUTHOR
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Omar E. Pol (info(AT)polprimos.com), Mar 01 2008
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EXTENSIONS
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More terms from Robert G. Wilson v, (rgwv(AT)rgwv.com), Apr 01 2008
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