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A274360
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Numbers n such that n and n+1 both have 18 divisors.
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2
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6075, 23275, 25856, 26900, 33524, 45324, 46475, 61299, 61347, 77076, 82075, 93924, 96236, 107775, 111924, 117324, 118700, 133524, 137924, 155771, 209524, 210176, 219275, 229275, 230643, 234099, 257724, 258475, 272924, 275300, 278271, 312987, 325899, 332667, 348524
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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) is(n)=numdiv(n)==18 && numdiv(n+1)==18
(PARI) list(lim)=my(v=List()); forprime(p=2, sqrtint(lim\12), forprime(q=2, sqrtint(lim\p^2\2), if(p==q, next); my(pq2=(p*q)^2); forprime(r=2, lim\pq2, if(p==r || q==r, next); t=pq2*r; if(numdiv(t-1)==18, listput(v, t-1)); if(numdiv(t+1)==18, listput(v, t))))); Set(v)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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