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

 

Logo

Annual Appeal: Today, Nov 11 2014, is the 4th anniversary of the launch of the new OEIS web site. 70,000 sequences have been added in these four years, all edited by volunteers. Please make a donation (tax deductible in the US) to help keep the OEIS running.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A014080 Factorions: equal to the sum of the factorials of their digits in base 10. 17
1, 2, 145, 40585 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Base 6 also has four factorions, as does base 15. - Alonso del Arte, Oct 20 2012

REFERENCES

J.-M. De Koninck, Ces nombres qui nous fascinent, Entry 145, p. 50, Ellipses, Paris 2008.

Clifford A. Pickover, A Passion for Mathematics, Wiley, 2005; see pp. 68, 305.

Joe Roberts, "The Lure of the Integers", page 35.

D. Wells, Curious and interesting numbers, Penguin Books, p. 125.

LINKS

Table of n, a(n) for n=1..4.

Project Euler, Problem 34

Eric Weisstein's World of Mathematics, Factorion

EXAMPLE

1! + 4! + 5! = 1 + 24 + 120 = 145, therefore 145 is in the sequence.

MATHEMATICA

Select[Range[50000], Plus @@ (IntegerDigits[ # ]!) == # &] (* Alonso del Arte, Jan 14 2008 *)

CROSSREFS

Cf. A193163.

Sequence in context: A188284 A228507 A071064 * A182478 A214910 A110624

Adjacent sequences:  A014077 A014078 A014079 * A014081 A014082 A014083

KEYWORD

nonn,fini,full,base

AUTHOR

David W. Wilson

EXTENSIONS

Additional reference from Felice Russo.

STATUS

approved

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

Content is available under The OEIS End-User License Agreement .

Last modified November 26 04:18 EST 2014. Contains 250017 sequences.