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).
MATHEMATICA
DeleteDuplicates[Table[{n, DivisorSigma[0, n(n-1)]}, {n, 2, 7*10^6}], GreaterEqual[#1[[2]], #2[[2]]]&][[;; , 1]] (* Harvey P. Dale, May 25 2024 *)
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
KEYWORD
nonn
AUTHOR
J. Lowell, Jul 02 2011
STATUS
approved