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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A124068 Fixed points for operation of repeatedly replacing a number by the sum of the seventh power of its digits. 9
0, 1, 1741725, 4210818, 9800817, 9926315, 14459929 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

The sequence "Fixed points for operation of repeatedly replacing a number by the sum of the sixth power of its digits" has just 3 terms: 0, 1, and 548834.

For a d-digit number n >= 10^(d-1), the sum of 7-th powers of its digits is <= 9^7*d, therefore these numbers cannot exceed 41205040. - M. F. Hasler, Apr 12 2015

LINKS

Table of n, a(n) for n=1..7.

EXAMPLE

1741725 = 1^7 + 7^7 + 4^7 + 1^7 + 7^7 + 2^7 + 5^7.

PROG

(PARI) isok(n) = my(d = digits(n)); sum(k=1, #d, d[k]^7) == n; \\ Michel Marcus, Feb 21 2015

(PARI) for(n=0, 41205040, A123253(n)==n&&print1(n", ")) \\ M. F. Hasler, Apr 12 2015

CROSSREFS

Cf. A046197, A052455, A052464, A124069, A226970, A003321.

Sequence in context: A234130 A177695 A252589 * A244073 A237307 A090054

Adjacent sequences:  A124065 A124066 A124067 * A124069 A124070 A124071

KEYWORD

base,fini,full,nonn

AUTHOR

S├ębastien Dumortier, Nov 05 2006

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 August 3 01:46 EDT 2015. Contains 260256 sequences.