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Positive numbers m where A217854(m) is positive and increases to a record.
4

%I #41 Sep 01 2023 03:59:34

%S 2,3,5,6,8,10,12,18,20,24,30,40,42,48,60,72,84,90,96,108,120,168,180,

%T 240,336,360,420,480,504,540,600,630,660,672,720,840,1080,1260,1440,

%U 1680,2160,2520,3360,3780,3960,4200,4320,4620,4680,5040,7560,9240,10080

%N Positive numbers m where A217854(m) is positive and increases to a record.

%C (-m)^tau(m) > 0 and (-m)^tau(m) > (-k)^tau(k) for all positive k < m, where tau is the number of divisors function.

%C There are no squares in this sequence.

%C It appears that if n > 13, then a(n) = A067128(n). See the link.

%C Only a finite number of terms in A002093 can also be terms in this sequence. See the link.

%H Simon Jensen, <a href="/A363658/b363658.txt">Table of n, a(n) for n = 1..135</a>

%H Simon Jensen, <a href="https://www.simonjensen.com/pdf/On_an_extended_divisor_product_summatory_function.pdf">On an extended divisor product summatory function</a>

%e 5 is a term since (-5)^tau(5) = (-5)^2 = 25 and 25 > (-k)^tau(k) for k = 1,...,4.

%o (PARI) isok(m) = my(x=(-m)^numdiv(m)); if (x>0, for (k=1, m-1, if (x <= (-k)^numdiv(k), return(0))); return(1)); \\ _Michel Marcus_, Aug 31 2023

%Y Cf. A363657, A067128, A000005, A002093, A217854, A224914.

%K nonn

%O 1,1

%A _Simon Jensen_, Jun 13 2023