A274360 Numbers n such that n and n+1 both have 18 divisors.
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
Offset: 1
Keywords
Links
- Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
Programs
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PARI
is(n)=numdiv(n)==18 && numdiv(n+1)==18
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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)