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 A228302 Composite squarefree numbers n such that p+d(n) divides n-d(n) for all prime factors p of n, where d(n) is the number of divisors of n. 16
 4958, 51653, 55583, 1251574, 4909102, 5430797, 5785073, 6096931, 13892243, 14058781, 14809517, 16699426, 27391073, 32426566, 32673383, 38669686, 43459682, 44762461, 53638783, 69836866, 74975761, 75226313, 85607461, 96973703, 105139141, 122864065 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Subsequence of A120944. LINKS Donovan Johnson, Table of n, a(n) for n = 1..100 EXAMPLE Prime factors of 51653 are 7, 47 and 157 while d(51653) = 8. We have that 51653 - 8 = 51645 and 51645 / (7 + 8) =  3443, 51645 / (47 + 8) = 939 and 51645 / (157 + 8) = 313. MAPLE with(numtheory);  P:=proc(q) local a, i, ok, p, n; for n from 1 to q do if not isprime(n) and issqrfree(n) then a:=ifactors(n)[2]; ok:=1; for i from 1 to nops(a) do if not type((n-tau(n))/(a[i][1]+tau(n)), integer) then ok:=0; break; fi; od; if ok=1 then print(n); fi; fi; od; end: P(10^9); CROSSREFS Cf. A000005, A228299-A228301. Sequence in context: A037044 A251847 A225718 * A116147 A233630 A254696 Adjacent sequences:  A228299 A228300 A228301 * A228303 A228304 A228305 KEYWORD nonn AUTHOR Paolo P. Lava, Aug 20 2013 EXTENSIONS More terms from Michel Marcus, Sep 21 2013 First term deleted by Paolo P. Lava, Sep 23 2013 STATUS approved

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Last modified May 16 18:05 EDT 2021. Contains 343949 sequences. (Running on oeis4.)