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Search: id:A064478
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| A064478 |
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For an integer n with prime factorization p1*p2*p3* ... *pn, a(n) = (p1+1)*(p2+1)*(p3+1)* ... *(pn+1). |
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+0
5
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| 1, 2, 3, 4, 9, 6, 12, 8, 27, 16, 18, 12, 36, 14, 24, 24, 81, 18, 48, 20, 54, 32, 36, 24, 108, 36, 42, 64, 72, 30, 72, 32, 243, 48, 54, 48, 144, 38, 60, 56, 162, 42, 96, 44, 108, 96, 72, 48, 324, 64, 108, 72, 126, 54, 192, 72, 216, 80, 90, 60, 216, 62, 96, 128, 729, 84, 144
(list; graph; listen)
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OFFSET
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0,2
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COMMENT
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a(0)=1 and a(1)=2 by convention.
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LINKS
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Harry J. Smith, Table of n, a(n) for n=0,...,1000
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PROGRAM
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(PARI) ns(n)= { local(f, p=1); f=factor(n); for(i=1, matsize(f)[1], p*=(1 + f[i, 1])^f[i, 2]); return(p) } { for (n=0, 1000, if (n>1, a=ns(n), a=n + 1); write("b064478.txt", n, " ", a) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Sep 15 2009]
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CROSSREFS
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Cf. A064476, A064479, A003958. Apart from initial terms, same as A003959.
Sequence in context: A091205 A106447 A060866 this_sequence A111798 A115305 A098550
Adjacent sequences: A064475 A064476 A064477 this_sequence A064479 A064480 A064481
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KEYWORD
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nonn,nice,easy
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com), Oct 06 2001
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EXTENSIONS
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More terms from Vladeta Jovovic (vladeta(AT)eunet.rs), Oct 06 2001
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