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!)
A050945 Six consecutive integers with decreasing values of sigma start at these numbers: sigma(x) > sigma(x+1) > sigma(x+2) > sigma(x+3) > sigma(x+4) > sigma(x+5). 1
20021154, 28503474, 53728674, 224539314, 242917674, 304178874, 341295954, 370845474, 377692314, 443998554, 533007474, 610484874, 709445274, 855529674, 964885074, 978052074, 1069943874, 1114988874, 1167961794 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

There are many examples of 4 consecutive numbers having decreasing values of sigma (see cross references) and there are 83 cases of 6 consecutive numbers with decreasing values of sigma < 4,293,000,000. Interestingly (and for unknown reasons) there are no examples of exactly 5 such consecutive numbers in that range! All known members of the sequence are multiples of 6 and one less than a multiple of 35.

REFERENCES

David Wells, The Penguin Dictionary of Curious and Interesting Numbers, entry 44.

LINKS

Table of n, a(n) for n=1..19.

EXAMPLE

sigma(20021154)=40894848 > sigma(20021155)=35458560 > ... > sigma(20021159)=20021160

CROSSREFS

Cf. A000203, A050944.

Sequence in context: A251513 A103123 A107618 * A251458 A116497 A133543

Adjacent sequences:  A050942 A050943 A050944 * A050946 A050947 A050948

KEYWORD

nonn

AUTHOR

Jud McCranie, Jan 02 2000

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 October 29 07:22 EDT 2020. Contains 338066 sequences. (Running on oeis4.)