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Divisors = 1 (mod 4) of Descartes's 198585576189.
4

%I #13 Feb 17 2017 08:46:10

%S 1,9,13,21,33,49,57,61,77,117,121,133,169,209,273,361,429,441,549,637,

%T 693,741,793,1001,1089,1197,1281,1521,1573,1617,1729,1881,2013,2541,

%U 2717,2793,2989,3249,3477,3549,4389,4693,4697,5577,5733,5929

%N Divisors = 1 (mod 4) of Descartes's 198585576189.

%C The number 198585576189 has 486 divisors, 246 of which are congruent to 1 modulo 4. - _M. F. Hasler_, Feb 17 2017

%H M. F. Hasler, <a href="/A033870/b033870.txt">Table of n, a(n) for n = 1..246</a>

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

%o (PARI) lista() = {fordiv(198585576189, d, if (d % 4 == 1, print1(d, ", ")));} \\ _Michel Marcus_, Jul 14 2013

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

%Y Cf. A033871, A222262.

%K easy,fini,nonn,full

%O 1,2

%A _Naohiro Nomoto_

%E Corrected by _Michel Marcus_, Jul 14 2013