login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A236433 List of primes generated by factoring successive primary pseudoperfect numbers (A054377). 5
2, 2, 3, 2, 3, 7, 2, 3, 7, 43, 2, 3, 11, 23, 31, 2, 3, 11, 23, 31, 47059, 2, 3, 11, 17, 101, 149, 3109, 2, 3, 11, 23, 31, 47059, 2217342227, 1729101023519 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

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

See A054377 for other comments, references, links, etc.

For prime factors of Giuga numbers, see A236434; of terms in Sylvester's sequence, see A126263.

LINKS

Table of n, a(n) for n=1..36.

EXAMPLE

2 = 2.

6 = 2 * 3.

42 = 2 * 3 * 7.

1806 = 2 * 3 * 7 * 43.

47058 = 2 *  3 * 11 * 23 * 31.

2214502422 =  2 *  3 * 11 * 23 * 31 * 47059.

52495396602 =  2 * 3 * 11 * 17 * 101 * 149 * 3109.

8490421583559688410706771261086 = 2 *  3 * 11 * 23 * 31 * 47059 * 2217342227 * 1729101023519.

CROSSREFS

Cf. A054377, A126263, A216825, A216826, A236434.

Sequence in context: A106245 A129568 A177892 * A117122 A122828 A242213

Adjacent sequences:  A236430 A236431 A236432 * A236434 A236435 A236436

KEYWORD

nonn,more,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 April 20 16:17 EDT 2019. Contains 322310 sequences. (Running on oeis4.)