|
|
A099678
|
|
Numbers n such that 10n01 is a prime.
|
|
3
|
|
|
3, 5, 6, 15, 17, 20, 21, 23, 27, 30, 38, 47, 48, 54, 56, 57, 65, 68, 71, 72, 83, 84, 90, 92, 102, 105, 110, 116, 122, 126, 134, 135, 143, 155, 156, 162, 164, 173, 182, 183, 197, 198, 200, 201, 203, 204, 210, 213, 222, 225, 227, 231, 233, 236, 249, 261, 264, 270, 281, 282, 290
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
MAPLE
|
t0:=[]; u0:=[]; for n from 0 to 500 do p0:="10"; p1:="01"; t1:=cat(p0, n, p1); t1:=convert(t1, decimal, 10); if isprime(t1) then t0:=[op(t0), n]; u0:=[op(u0), t1]; fi; od: t0;
# Alternative:
filter:= n -> isprime( 10^(ilog10(n)+4)+100*n+1):
|
|
MATHEMATICA
|
Select[ Range[280], PrimeQ[ FromDigits[Join[{1, 0}, IntegerDigits[ # ], {0, 1}]]] &] (* Robert G. Wilson v, Nov 20 2004 *)
|
|
PROG
|
(PARI) isok(n) = isprime(eval(concat(concat("10", n), "01"))); \\ Michel Marcus, Jul 29 2015
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,base
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|