login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A108257 Numbers n such that concatenating n and the sum of factorials of the digits of n produces a prime. 0
1, 13, 15, 30, 31, 91, 101, 110, 128, 133, 136, 138, 144, 152, 156, 166, 175, 193, 199, 203, 215, 230, 250, 260, 280, 281, 303, 304, 306, 307, 309, 315, 320, 330, 331, 340, 361, 391, 412, 508, 520, 550, 606, 651, 661, 681, 708, 712, 717, 730, 750, 751, 780 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

The largest prime I have found pertaining to this sequence is A109016(Fibonacci(9837)) with 2064 digits (not proved prime, only Fermat and Lucas PRP).

LINKS

Table of n, a(n) for n=1..53.

EXAMPLE

193 is in the sequence because 1!+9!+3! = 362887 and 193362887 is prime.

CROSSREFS

Cf. A061602, A109016.

Sequence in context: A087814 A227449 A113801 * A217252 A299593 A318543

Adjacent sequences:  A108254 A108255 A108256 * A108258 A108259 A108260

KEYWORD

base,nonn

AUTHOR

Jason Earls, Jun 18 2005

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 30 19:43 EDT 2022. Contains 354945 sequences. (Running on oeis4.)