A033870 Divisors = 1 (mod 4) of Descartes's 198585576189.

1, 9, 13, 21, 33, 49, 57, 61, 77, 117, 121, 133, 169, 209, 273, 361, 429, 441, 549, 637, 693, 741, 793, 1001, 1089, 1197, 1281, 1521, 1573, 1617, 1729, 1881, 2013, 2541, 2717, 2793, 2989, 3249, 3477, 3549, 4389, 4693, 4697, 5577, 5733, 5929

Offset: 1

Author

Naohiro Nomoto

Keywords

• easy
• fini
• nonn
• full

Comments

The number 198585576189 has 486 divisors, 246 of which are congruent to 1 modulo 4. - M. F. Hasler, Feb 17 2017

Examples

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

Links

• M. F. Hasler, Table of n, a(n) for n = 1..246

Crossrefs

Cf. A033871, A222262.

Programs

PARI

lista() = {fordiv(198585576189, d, if (d % 4 == 1, print1(d, ", ")));} \\ Michel Marcus, Jul 14 2013

PARI

select(d->d%4==1, divisors(198585576189)) \\ M. F. Hasler, Feb 17 2017

Extensions

Corrected by Michel Marcus, Jul 14 2013