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Divisors = 3 (mod 4) of Descartes's 198585576189.
4

%I #15 Jan 07 2023 11:44:05

%S 3,7,11,19,39,63,91,99,143,147,171,183,231,247,363,399,427,507,539,

%T 627,671,819,847,931,1083,1159,1183,1287,1463,1859,1911,2223,2299,

%U 2379,2527,3003,3211,3843,3971,4719,4851,5187,5551,6039

%N Divisors = 3 (mod 4) of Descartes's 198585576189.

%C The number 198585576189 (which is the only known odd spoof-perfect number, cf. A174292) has 486 divisors, 240 of which are congruent to 3 modulo 4. - _M. F. Hasler_, Feb 17 2017

%H M. F. Hasler, <a href="/A033871/b033871.txt">Table of n, a(n) for n = 1..240</a>

%e 198585576189 = 3^2 * 7^2 * 11^2 * 13^2 * 19^2 * 61.

%t Select[Divisors[198585576189],Mod[#,4]==3&] (* _Harvey P. Dale_, Jan 07 2023 *)

%o (PARI) lista() = {fordiv(198585576189, d, if (d % 4 == 3, print1(d, ", ")));} \\ _Michel Marcus_, Jul 14 2013

%o (PARI) select(d->d%4==1, divisors(198585576189)) \\ _M. F. Hasler_, Feb 17 2017

%Y Cf. A033870, A222262.

%K easy,fini,nonn,full

%O 1,1

%A _Naohiro Nomoto_

%E Corrected by _Michel Marcus_, Jul 14 2013