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A344755 Numbers k such that A344753(k) is a multiple of A048250(k), and k is a multiple of A344753(k)/A048250(k). 7

%I #14 May 31 2021 21:23:56

%S 6,28,150,496,528,1980,4560,8128,8736,11400,19872,20664,75840,82080,

%T 253080,254880,741744,1627290,5130300,5607360,7529760,19645440,

%U 20718720,33550336,35092512,45643392,45995040,56424960,86944320,169910136,174013920,180442080,196378992,242040960,304577280,314511360,326611440,451344960

%N Numbers k such that A344753(k) is a multiple of A048250(k), and k is a multiple of A344753(k)/A048250(k).

%C Numbers k for which A344753(k)/A048250(k) is a divisor of k.

%C Perfect numbers (A000396, including also any hypothetical odd terms) are included as only on them A001615 coincides with A344753, and because A001615(n) = A003557(n)*A048250(n), with A003557(n) being a divisor of n.

%H Antti Karttunen, <a href="/A344755/b344755.txt">Table of n, a(n) for n = 1..50 (terms < 2^31)</a>

%H <a href="/index/O#opnseqs">Index entries for sequences where odd perfect numbers must occur, if they exist at all</a>

%o (PARI)

%o A048250(n) = factorback(apply(p -> p+1,factor(n)[,1]));

%o A344753(n) = sumdiv(n,d,(d<n)*(d+(issquarefree(n/d) * d)));

%o isA344755(n) = { my(t=A344753(n),u=A048250(n)); ((0==(t%u))&&(0==(n%(t/u)))); };

%Y Cf. A000396 (subsequence), A001065, A001615, A003557, A306927, A048250, A344753.

%Y Subsequence of A344754.

%Y Cf. also A344700.

%K nonn

%O 1,1

%A _Antti Karttunen_, May 29 2021

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Last modified July 18 21:02 EDT 2024. Contains 374388 sequences. (Running on oeis4.)