This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A343731 #26 Jul 21 2024 15:45:45 %S A343731 0,2,3,4,6,10,12,18,20,24,30,42,60,78,84,90,114,120,140,150,156,168, %T A343731 180,210,330,390,420,510,546,570,630,660,780,840,990,1020,1050,1092, %U A343731 1140,1170,1260,1530,1540,1560,1680,1848,1890,1980,2100,2280,2310,2730,3570 %N A343731 Numbers k at which tau(k^k) reaches a record high, where tau is the number-of-divisors function A000005. %H A343731 Jon E. Schoenfield, <a href="/A343731/b343731.txt">Table of n, a(n) for n = 1..10000</a> (first 510 terms from Chai Wah Wu) %e A343731 In the table below, asterisks indicate record high values of tau(k^k): %e A343731 tau(k^k) = %e A343731 k k^k = A000312(k) A062319(k) %e A343731 -- ---------------- ---------- %e A343731 0 1 1 * %e A343731 1 1 1 %e A343731 2 4 3 * %e A343731 3 27 4 * %e A343731 4 256 9 * %e A343731 5 3125 6 %e A343731 6 46656 49 * %e A343731 7 823543 8 %e A343731 8 16777216 25 %e A343731 9 387420489 19 %e A343731 10 10000000000 121 * %e A343731 11 285311670611 12 %e A343731 12 8916100448256 325 * %e A343731 . %e A343731 The numbers k at which those record high values occur are 0, 2, 3, 4, 5, 6, 10, 12, ... %t A343731 Join[{0},DeleteDuplicates[Table[{n,DivisorSigma[0,n^n]},{n,2,3600}],GreaterEqual[ #1[[2]],#2[[2]]]&][[;;,1]]] (* _Harvey P. Dale_, Jul 21 2024 *) %o A343731 (Python) %o A343731 from functools import reduce %o A343731 from operator import mul %o A343731 from sympy import factorint %o A343731 c, A343731_list = 0, [0] %o A343731 for n in range(2,10**5): %o A343731 x = reduce(mul,(n*d+1 for d in factorint(n).values())) %o A343731 if x > c: %o A343731 c = x %o A343731 A343731_list.append(n) # _Chai Wah Wu_, Jun 03 2021 %Y A343731 Cf. A000005, A000312, A062319. %K A343731 nonn %O A343731 1,2 %A A343731 _Jon E. Schoenfield_, Jun 01 2021