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5, 7, 13, 16, 19, 31, 36, 40, 41, 43, 49, 50, 53, 61, 74, 82, 84, 89, 92, 94, 102, 103, 107, 109, 113, 130, 138, 140, 149, 151, 154, 158, 169, 181, 182, 197, 199, 217, 229, 233, 239, 241, 243, 257, 266, 271, 293, 331, 349, 361, 383, 389, 409, 419, 421, 439, 463
(list;
graph;
refs;
listen;
history;
text;
internal format)
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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) f(n) = s=0; for(x=1, n^2, if(sigma(x)-x-1==n, s++)); s ud(n) = 2^omega(n); j=[]; for(n=1, 150, if(f(n)==ud(n), j=concat(j, n))); j
(PARI) f(n)= { local(s=0); for(x=1, n^2, if(sigma(x) - x - 1==n, s++)); return(s) } ud(n)= { 2^omega(n) } { n=0; for (m=1, 10^9, if (f(m)==ud(m), write("b064465.txt", n++, " ", m); if (n==100, break)) ) } \\ Harry J. Smith, Sep 15 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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EXTENSIONS
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STATUS
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approved
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