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Search: id:A079616
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| A079616 |
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Number of occurrences of prime factorization templates. |
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+0
2
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| 1, 1, 1, 2, 1, 3, 1, 4, 2, 3, 1, 5, 1, 3, 3, 6, 1, 7, 1, 5, 3, 3, 1, 8, 2, 3, 4, 5, 1, 9, 1, 10, 3, 3, 3, 11, 1, 3, 3, 8, 1, 9, 1, 5, 5, 3, 1, 12, 2, 7, 3, 5, 1, 13, 3, 8, 3, 3, 1, 14, 1, 3, 5, 15, 3, 9, 1, 5, 3, 9, 1, 16, 1, 3, 7, 5, 3, 9, 1, 12, 6, 3, 1, 14, 3, 3, 3, 8, 1, 17, 3, 5, 3, 3, 3, 18, 1, 7, 5, 11
(list; graph; listen)
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OFFSET
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2,4
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COMMENT
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1=p, 2=p^2, 3=p.q, 4=p^3, 5=p^2.q, 6=p^4 7=p.q^2, 8=p^3.q, 9=p.q.r, 10=p^5, 11=p^2.q^2, 12=p^4.q (p<q<r)
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FORMULA
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a(n) = A077462(n) - 1. - David Wasserman (wasserma(AT)spawar.navy.mil), Dec 21 2004
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EXAMPLE
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Primes are given 1. The next prime factorization pattern is 4=p^2, so a(4)=2 and similarly a(6)=3.
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PROGRAM
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(PARI) primetemplate(n)=local(f, fl, res, eres); f=factor(n); fl=length(f[, 1]); res=""; for (i=1, fl, res=concat(res, f[, 2][i])); eres=eval(res); if (v[eres]==0, v[eres]=vc; vc++); eres vc=1; v=vector(10000); for (j=2, 50, print1(v[primetemplate(j)]", "))
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CROSSREFS
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Cf. A037916.
Sequence in context: A067004 A117920 A079617 this_sequence A097283 A118314 A002033
Adjacent sequences: A079613 A079614 A079615 this_sequence A079617 A079618 A079619
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KEYWORD
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nonn
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AUTHOR
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Jon Perry (perry(AT)globalnet.co.uk), Jan 29 2003
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EXTENSIONS
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More terms from David Wasserman (wasserma(AT)spawar.navy.mil), Dec 21 2004
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