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A036438
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Integers which can be written as m*tau(m) for some m, where tau = A000005.
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5
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1, 4, 6, 10, 12, 14, 22, 24, 26, 27, 32, 34, 38, 40, 46, 56, 58, 60, 62, 72, 74, 75, 80, 82, 84, 86, 88, 94, 104, 106, 108, 118, 120, 122, 132, 134, 136, 140, 142, 146, 147, 152, 156, 158, 166, 168, 178, 184, 192, 194, 202, 204, 206, 214, 218, 220, 226, 228, 232
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OFFSET
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1,2
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COMMENTS
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Invented by the HR concept formation program.
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LINKS
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EXAMPLE
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10 = 5 * tau(5).
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PROG
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(PARI) isok(n) = {for (k=1, n, if (k*numdiv(k) == n, return (1)); ); return (0); } \\ Michel Marcus, Dec 09 2014
(PARI)
up_to = 65536;
A036438list(up_to) = { my(v=vector(up_to), m = Map()); for(n=1, #v, mapput(m, n*numdiv(n), n)); my(k=0, u=0); while((k<#v)&&(u<#v), u++; if(mapisdefined(m, u), k++; v[k] = u)); vector(k, i, v[i]); };
v036438 = A036438list(up_to);
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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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Simon Colton (simonco(AT)cs.york.ac.uk)
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STATUS
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approved
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