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Search: id:A064111
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| A064111 |
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Numbers n such that sopf(n)+1 = sopf(n+1), where sopf(n)=A008472(n). |
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1
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| 2, 8, 120, 168, 175, 247, 860, 1044, 1444, 1659, 1849, 3626, 3834, 4233, 4300, 4345, 4814, 6867, 8240, 14905, 23287, 24476, 28919, 29087, 29464, 30457, 30650, 33725, 34945, 35585, 37214, 49468, 52206, 54900, 58113, 62049, 63440, 65631, 68264
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Also n such that z(n) = z(n+1) where z(n) = n-sopf(n).
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LINKS
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Harry J. Smith, Table of n, a(n) for n=1,...,1000
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EXAMPLE
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sopf(8)+1=3, sopf(8+1)=3.
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PROGRAM
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(PARI) sopf(n, s, fac, i)=fac=factor(n); for(i=1, matsize(fac)[1], s=s+fac[i, 1]); return(s); j=[]; for(n=1, 100000, if(sopf(n)+1==sopf(n+1), j=concat(j, n))); j
(PARI) z(n)= { local(f, s=0); f=factor(n); for(i=1, matsize(f)[1], s+=f[i, 1]); return(n - s) } { n=0; zm=z(1); for (m=1, 10^9, zp=z(m + 1); if (zm==zp, write("b064111.txt", n++, " ", m); if (n==1000, break)); zm=zp ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Sep 07 2009]
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CROSSREFS
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Cf. A006145.
Sequence in context: A012343 A012347 A099292 this_sequence A112094 A009658 A147794
Adjacent sequences: A064108 A064109 A064110 this_sequence A064112 A064113 A064114
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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), Sep 08 2001
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