A063506 revision #6
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A063506
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a(n) = phi(a(n-1) * number of divisors of a(n-1), a(1)=3.
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1
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3, 4, 6, 8, 16, 40, 128, 512, 2560, 20480, 212992, 2949120, 80216064, 3019898880, 130459631616, 7827577896960, 935134639423488, 128247036263792640, 22024291027701989376, 7222873082376801484800, 4118350906606118082969600
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OFFSET
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1,1
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LINKS
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PROG
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(PARI) s(n)=if(n<2, n+2, eulerphi(s(n-1))*numdiv(s(n-1)) ); for(n=1, 22, print(s(n)))
(PARI) { for (n=1, 148, if (n>1, a=eulerphi(a)*numdiv(a), a=3); write("b063506.txt", n, " ", a) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Aug 24 2009]
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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Jason Earls (zevi_35711(AT)yahoo.com), Aug 09 2001
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STATUS
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approved
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