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!)
A161848 Primes with at least one digit appearing exactly three times in the decimal expansion. 0
1117, 1151, 1171, 1181, 1511, 1777, 1811, 1999, 2111, 2221, 2333, 2777, 2999, 3313, 3323, 3331, 3343, 3373, 3433, 3533, 3733, 3833, 4111, 4441, 4447, 4999, 5333, 5557, 6661, 7177, 7333, 7477, 7577, 7717, 7727, 7757, 7877, 8111, 8887, 8999, 9199, 9929 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Sequence is probably infinite.

LINKS

Table of n, a(n) for n=1..42.

EXAMPLE

2333, 3313, 3833 all repeat some digit 3 three times.

MAPLE

isdgctm := proc(n, d) local dgs, a, i ; dgs := convert(n, base, 10) ; a := [seq(0, j=0..9)] ;

for i in dgs do a := subsop(i+1=op(i+1, a)+1, a) ; od: if convert(a, set) intersect {d} <> {} then true; else false; fi; end:

for n from 1 to 2000 do p := ithprime(n) ; if isdgctm(p, 3) then printf("%d, ", p) ; fi; od: # R. J. Mathar, Jun 21 2009

CROSSREFS

Cf. A161786, A161796.

Sequence in context: A260103 A258691 A221428 * A020380 A243527 A251360

Adjacent sequences:  A161845 A161846 A161847 * A161849 A161850 A161851

KEYWORD

nonn,base

AUTHOR

Ki Punches, Jun 20 2009

EXTENSIONS

Edited and corrected by R. J. Mathar, Jun 21 2009

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 May 27 16:48 EDT 2022. Contains 354110 sequences. (Running on oeis4.)