login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A236434 Table whose n-th row lists the prime factors of the n-th Giuga number A007850(n). 6
2, 3, 5, 2, 3, 11, 13, 2, 3, 7, 41, 2, 3, 11, 17, 59, 2, 3, 11, 23, 31, 47057, 2, 3, 7, 43, 3041, 4447, 2, 3, 7, 59, 163, 1381, 775807, 2, 3, 7, 71, 103, 67213, 713863, 2, 3, 7, 71, 103, 61559, 29133437, 2, 3, 11, 23, 31, 47137, 28282147, 3892535183, 2, 3, 11, 23, 31, 47059, 2259696349, 110725121051, 2, 3, 7, 43, 1831, 138683, 2861051, 1456230512169437 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

It is unknown whether there are infinitely many Giuga numbers or any odd ones.

See A007850 for other comments, references, links, etc.

For prime factors of primary pseudoperfect numbers, see  A236433; of terms in Sylvester's sequence, see A126263.

LINKS

M. F. Hasler, Table of n, a(n) for n = 1..73

EXAMPLE

30 = 2 * 3 * 5.

858 = 2 * 3 * 11 * 13.

1722 = 2 * 3 * 7 * 41.

66198 = 2 * 3 * 11 * 17 * 59.

2214408306 = 2 * 3 * 11 * 23 * 31 * 47057.

24423128562 = 2 * 3 * 7 * 43 * 3041 * 4447.

432749205173838 = 2 * 3 * 7 * 59 * 163 * 1381 * 775807.

14737133470010574 = 2 * 3 * 7 * 71 * 103 * 67213 * 713863.

550843391309130318 = 2 * 3 * 7 * 71 * 103 * 61559 * 29133437.

244197000982499715087866346 = 2 * 3 * 11 * 23 * 31 * 47137 * 28282147 * 3892535183.

554079914617070801288578559178 = 2 * 3 * 11 * 23 * 31 * 47059 * 2259696349 * 110725121051.

1910667181420507984555759916338506 = 2 * 3 * 7 * 43 * 1831 * 138683 * 2861051 * 1456230512169437.

Another Giuga number (but possibly not the 13th) is 4200017949707747062038711509670656632404195753751630609228764416142557211582098432545190323474818 = 2 * 3 * 11 * 23 * 31 * 47059 * 2217342227 * 1729101023519 * 8491659218261819498490029296021 * 58254480569119734123541298976556403.

CROSSREFS

Cf. A007850, A216823, A216824, A236433.

Sequence in context: A060084 A265668 A273087 * A138182 A167835 A102044

Adjacent sequences:  A236431 A236432 A236433 * A236435 A236436 A236437

KEYWORD

nonn,tabf,hard

AUTHOR

Jonathan Sondow, Jan 25 2014

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 14 00:36 EDT 2020. Contains 335716 sequences. (Running on oeis4.)