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 A192488 Numbers that set records for number of divisors of n(n-1). 1
 2, 3, 4, 6, 9, 15, 16, 21, 36, 64, 81, 100, 105, 196, 225, 385, 441, 561, 936, 1225, 1540, 2016, 2080, 5265, 5985, 12376, 21736, 41041, 78625, 123201, 126225, 156520, 176176, 201825, 313600, 338625, 395200, 453376, 638001, 1154440, 1890945, 2203201, 2697696, 2756160, 4921840, 6969600 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Places of records in A092517. Bases for which it is easy to find divisibility rules for many numbers in those bases; in base 64 the final digit rule works for 1,2,4,8,16,32,64 and the add the digits rule works for 1,3,7,9,21,63. LINKS Charles R Greathouse IV, Table of n, a(n) for n = 1..61 EXAMPLE 6 qualifies because 6*5=30 has 8 divisors, more than any smaller number of the form n(n-1). PROG (PARI) r=0; t1=1; for(n=2, 1e8, t2=numdiv(n); if(t1*t2>r, r=t1*t2; print1(n", ")); t1=t2) \\ Charles R Greathouse IV, Jul 03 2011 CROSSREFS Sequence in context: A173278 A173289 A096824 * A089797 A081237 A022159 Adjacent sequences:  A192485 A192486 A192487 * A192489 A192490 A192491 KEYWORD nonn AUTHOR J. Lowell, Jul 02 2011 STATUS approved

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Last modified December 3 14:51 EST 2020. Contains 338906 sequences. (Running on oeis4.)