|
| |
|
|
A161786
|
|
Primes with at least one digit appearing exactly four times in the decimal expansion.
|
|
3
| |
|
|
10111, 11113, 11117, 11119, 11131, 11161, 11171, 11311, 11411, 16111, 22229, 23333, 31333, 33331, 33343, 33353, 33533, 38333, 44449, 47777, 49999, 59999, 67777, 71777, 76777, 77377, 77477, 77747, 77773, 77797, 77977, 79777, 79999, 88883, 94999, 97777
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
COMMENTS
| The sequence is probably infinite.
|
|
|
EXAMPLE
| 101117 has exactly four 1s.
|
|
|
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 10000 do p := ithprime(n) ; if isdgctm(p, 4) then printf("%d, ", p) ; fi; od: # R. J. Mathar, Jun 21 2009
|
|
|
CROSSREFS
| Sequence in context: A114385 A144863 A058042 * A157711 A159863 A054037
Adjacent sequences: A161783 A161784 A161785 * A161787 A161788 A161789
|
|
|
KEYWORD
| nonn,base
|
|
|
AUTHOR
| Ki Punches (ki1212(AT)pocketmail.com), Jun 19 2009
|
|
|
EXTENSIONS
| Edited and corrected by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jun 21 2009
|
| |
|
|
