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A105106
Numbers k such that the string k101 is prime.
4
0, 5, 6, 8, 12, 15, 20, 21, 29, 42, 44, 50, 53, 54, 56, 60, 65, 72, 74, 77, 78, 81, 83, 89, 95, 98, 102, 107, 116, 117, 119, 125, 131, 135, 138, 141, 149, 170, 174, 177, 182, 194, 197, 201, 204, 210, 221, 224, 230, 240, 242, 243, 252, 258, 261, 263, 264, 282, 285, 291
OFFSET
1,2
COMMENTS
Also numbers k such that 1000*k + 101 is prime. - Stefan Steinerberger, Feb 21 2006
LINKS
EXAMPLE
If k=0, then k101 = 0101 (prime).
If k=42, then k101 = 42101 (prime).
MAPLE
q:= n-> isprime(parse(cat(n, 101))):
select(q, [$0..300])[]; # Alois P. Heinz, Jan 23 2020
MATHEMATICA
For[n = 0, n < 300, n++, If[PrimeQ[1000*n + 101], Print[n]]] (* Stefan Steinerberger, Feb 21 2006 *)
PROG
(PARI) is(n)=isprime(1000*n+101) \\ Charles R Greathouse IV, May 22 2017
CROSSREFS
Sequence in context: A033158 A193569 A032721 * A140504 A120131 A047437
KEYWORD
base,nonn
AUTHOR
Parthasarathy Nambi, Apr 07 2005
EXTENSIONS
More terms from Stefan Steinerberger, Feb 21 2006
Missing a(11)=44 inserted by Daniel Starodubtsev, Jan 23 2020
STATUS
approved