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%I #7 Aug 06 2024 11:11:09
%S 6,24,72,210,5400,30720,36960,51840,53760,120120,264600,887040,
%T 3991680,6912000,14968800,22118400,58198140,319334400,1703116800,
%U 4151347200,6273146880,12247200000,31757806080,42343741440,47636709120,70572902400,238378140000,442810368000
%N Smaller of two successive terms of A025487 that have an equal number of divisors.
%C There are runs of three successive terms of A025487 that have an equal number of divisors. The smallest elements in these runs are 51840, 17149215283200, 63147292984115358771227840741376000000000, ... . Are there such runs of four successive terms?
%H Amiram Eldar, <a href="/A375196/b375196.txt">Table of n, a(n) for n = 1..4390</a>
%F a(n) = A025487(A375195(n)).
%e 6 is a term since 6 and 8 are two successive terms of A025487, and they have an equal number of divisors: A000005(6) = A000005(8) = 4.
%t With[{lps = Cases[Import["https://oeis.org/A025487/b025487.txt", "Table"], {_, _}][[;; , 2]]}, lps[[Position[Differences[DivisorSigma[0, lps]], 0] // Flatten]]]
%Y Cf. A000005, A025487, A146288, A375195.
%K nonn
%O 1,1
%A _Amiram Eldar_, Aug 04 2024