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Numbers k such that k^2 is a member of A072498.
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%I #14 Dec 11 2024 09:28:09

%S 2,3,4,5,6,7,9,10,11,13,14,15,16,17,18,19,20,21,22,23,24,25,26,28,29,

%T 30,31,33,34,35,36,37,38,39,40,41,42,43,44,46,47,48,49,50,51,52,53,54,

%U 55,56,57,58,59,60,61,62,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78

%N Numbers k such that k^2 is a member of A072498.

%C p^m are members of the sequence, where p is prime and m different from k(4k-1) and k(4k+1) (spatially all primes, p^1).

%C Complement of A072327 in the positive integers. - _Robert Israel_, Dec 10 2024

%H Robert Israel, <a href="/A072497/b072497.txt">Table of n, a(n) for n = 1..10000</a>

%p filter:= proc(n) local s, F, d, p;

%p s:= n^2;

%p F:= sort(convert(numtheory:-divisors(s), list));

%p p:= 1:

%p for d in F do

%p p:= p*d;

%p if p > s then return true

%p elif p = s then return false

%p fi

%p od;

%p end proc:

%p select(filter, [$1..100]); # _Robert Israel_, Dec 10 2024

%Y Cf. A072498, A072327, A072510.

%K nonn

%O 1,1

%A _Vladimir Baltic_, Aug 04 2002