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 A275250 Odd numbers n that divide the number of divisors of n!. 1
 1, 27, 45, 105, 125, 135, 175, 189, 225, 231, 243, 297, 315, 351, 375, 385, 405, 441, 455, 495, 525, 539, 567, 585, 595, 605, 625, 637, 663, 675, 693, 715, 729, 735, 741, 765, 819, 825, 845, 847, 855, 875, 891, 935, 945, 969, 975, 1001, 1029, 1035, 1045, 1053, 1089 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Odd terms of A051178. LINKS Robert Israel, Table of n, a(n) for n = 1..10000 EXAMPLE The odd number 27 is a term because A000005(27!) = 2^9*3^3*7^2 is divisible by 27. MAPLE N:= 2000: # to get all terms <= N P:= select(isprime, [2, seq(i, i=3..N, 2)]): d:= Vector(nops(P), 1): A:= 1: for n from 2 to N do   f:= ifactors(n)[2];   for t in f do     if member(t[1], P, 'k') then         d[k]:= d[k] + t[2]     fi   od:   if n::odd and convert(d, `*`) mod n = 0 then A:= A, n fi; od: A; # Robert Israel, Aug 05 2016 MATHEMATICA A275250Q = OddQ[#] && Divisible[DivisorSigma[0, #!], #] &; Select[Range[500], A275250Q] (* JungHwan Min, Jul 29 2016 *) PROG (PARI) isok(n) = (n % 2) && !(numdiv(n!) % n); \\ Michel Marcus, Jul 26 2016 CROSSREFS Cf. A051178, A027423. Sequence in context: A039325 A043148 A043928 * A223019 A059658 A241407 Adjacent sequences:  A275247 A275248 A275249 * A275251 A275252 A275253 KEYWORD nonn AUTHOR Altug Alkan, Jul 21 2016 STATUS approved

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Last modified April 18 08:37 EDT 2019. Contains 322209 sequences. (Running on oeis4.)