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

1,2

Comments

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

Links

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

Example

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

Prog

(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

Crossrefs

Cf. A033871, A222262.

Sequence in context: A304259 A124249 A137168 * A151901 A157199 A291351

Adjacent sequences: A033867 A033868 A033869 * A033871 A033872 A033873

Keyword

easy,fini,nonn,full

Author

Naohiro Nomoto

Extensions

Corrected by Michel Marcus, Jul 14 2013

Status

approved