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!)
A090152 Primes of the form identical digits preceded by a 4. 2
41, 43, 47, 433, 499, 4111, 4999, 47777, 49999, 4999999, 41111111111111, 47777777777777, 499999999999999, 43333333333333333, 41111111111111111111111111, 47777777777777777777777777 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
MATHEMATICA
Select[ FromDigits /@ Flatten[ Table[ PadRight[{4}, i, # ] & /@ {1, 2, 3, 4, 5, 6, 7, 8, 9}, {i, 2, 24}], 1], PrimeQ[ # ] &]
Select[Flatten[Table[FromDigits[PadRight[{4}, n, k]], {n, 2, 30}, {k, {1, 3, 7, 9}}]], PrimeQ] (* Harvey P. Dale, Apr 23 2019 *)
CROSSREFS
Sequence in context: A062669 A284290 A045710 * A139774 A007643 A259552
KEYWORD
nonn,base
AUTHOR
Robert G. Wilson v, Nov 22 2003
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 24 02:53 EDT 2024. Contains 373661 sequences. (Running on oeis4.)