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A064678
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Numbers k such that sopf(k) = sopfr(k+1), where sopf(k) = A008472(k) and sopfr(k) = A001414(k).
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1
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5, 15, 77, 99, 104, 153, 369, 492, 539, 714, 1330, 2491, 4191, 5405, 5831, 5959, 6556, 6579, 6723, 8463, 9424, 12221, 12351, 12726, 13419, 14587, 21716, 24432, 24880, 24895, 26642, 30267, 31487, 33019, 35456, 38324, 43215, 43802, 44831, 45524
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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) sopf(n)= { local(f, s=0); f=factor(n); for(i=1, matsize(f)[1], s+=f[i, 1]); return(s) } sopfr(n)= { local(f, s=0); f=factor(n); for(i=1, matsize(f)[1], s+=f[i, 1]*f[i, 2]); return(s) } { n=0; for (m=1, 10^9, if (sopf(m)==sopfr(m + 1), write("b064678.txt", n++, " ", m); if (n==500, break)) ) } \\ Harry J. Smith, Sep 22 2009
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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