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 A137490 Numbers with 27 divisors. 1
 900, 1764, 2304, 4356, 4900, 6084, 6400, 10404, 11025, 12100, 12544, 12996, 16900, 19044, 23716, 26244, 27225, 28900, 30276, 30976, 33124, 34596, 36100, 38025, 43264, 49284, 52900, 53361, 56644, 60516, 65025, 66564, 70756, 73984, 74529 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Maple implementation: see A030513. Numbers of the form p^26 (subset of A089081), p^2*q^2*r^2 (like 900, 1764, 4356, squares of A007304) or p^2*q^8 (like 2304, 6400, subset of the squares of A030628) where p, q and r are distinct primes. - R. J. Mathar, Mar 01 2010 LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..1000 FORMULA A000005(a(n))=27. MATHEMATICA Select[Range[150000], DivisorSigma[0, #]==27&] (* Vladimir Joseph Stephan Orlovsky, May 06 2011 *) PROG (PARI) isA137490(n) = numdiv(n)==27 \\ Michael B. Porter, Apr 10 2010 CROSSREFS Cf. A030513..A030516, A030626, A030627, A030634..A030638, A005179, A003680, A096932, A061286, A061283. Sequence in context: A061044 A127658 A318720 * A129575 A328136 A321206 Adjacent sequences:  A137487 A137488 A137489 * A137491 A137492 A137493 KEYWORD nonn AUTHOR R. J. Mathar, Apr 22 2008 STATUS approved

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Last modified February 16 15:17 EST 2020. Contains 331961 sequences. (Running on oeis4.)