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 A079788 a(n) = count of numbers <= n for which the number of divisors is also <= tau(n). 2
 1, 2, 3, 4, 4, 6, 5, 8, 7, 10, 6, 12, 7, 13, 14, 15, 8, 18, 9, 20, 17, 18, 10, 24, 13, 21, 22, 27, 11, 30, 12, 30, 25, 26, 27, 36, 13, 29, 30, 39, 14, 41, 15, 39, 40, 33, 16, 48, 20, 44, 36, 46, 17, 52, 38, 54, 39, 40, 18, 60, 19, 43, 54, 55, 44, 63, 20, 57, 46, 67, 21, 72, 22, 49 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS EXAMPLE a(7) = 5 as 1, 2, 3, 5 and 7 qualify for the count. MATHEMATICA Do[s = 0; For[i = 1, i <= n, i++, If[DivisorSigma[0, i] <= DivisorSigma[0, n], s++ ]]; Print[s], {n, 1, 50}] - Ryan Propper, Mar 30 2006 PROG (PARI) for(n=1, 200, m=0; sn=sigma(n, 0); for(i = 1, n, if(sigma(i, 0)<=sn, m++)); print1(m", ")) - Herman Jamke (hermanjamke(AT)fastmail.fm), Apr 28 2007 CROSSREFS Cf. A138009, A067004. Sequence in context: A071324 A063655 A117248 * A146288 A244361 A199424 Adjacent sequences:  A079785 A079786 A079787 * A079789 A079790 A079791 KEYWORD nonn AUTHOR Amarnath Murthy, Feb 03 2003 EXTENSIONS More terms from Ryan Propper, Mar 30 2006 More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Apr 28 2007 STATUS approved

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