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A099192
Numbers k such that the string k235711131719 is prime.
2
5, 12, 20, 23, 30, 32, 38, 39, 57, 62, 65, 66, 72, 108, 117, 120, 123, 141, 143, 144, 170, 176, 194, 198, 207, 215, 221, 225, 240, 255, 269, 293, 297, 305, 309, 320, 321, 324, 426, 446, 458, 471, 480, 488, 512, 521, 540, 551, 557, 566, 569, 570, 573, 594, 599
OFFSET
1,1
COMMENTS
Also numbers k such that (10^12*k + 235711131719) is prime. - Stefan Steinerberger, Feb 15 2006
LINKS
EXAMPLE
If k = 5, then k235711131719 = 5235711131719 (prime).
If k = 38, then k235711131719 = 38235711131719 (prime).
If k = 72, then k235711131719 = 72235711131719 (prime).
MAPLE
q:= n-> isprime(parse(cat(n, 235711131719))):
select(q, [$1..1000])[]; # Alois P. Heinz, May 12 2021
MATHEMATICA
For[n = 1, n < 500, n++, If[PrimeQ[10^12*n + 235711131719], Print[n]]] (* Stefan Steinerberger, Feb 15 2006 *)
PROG
(PARI) ok(n)={isprime(n*10^12+235711131719)} \\ Andrew Howroyd, Jan 23 2020
(Python)
from sympy import isprime
def aupto(limit):
alst = []
for k in range(1, limit+1):
if isprime(10**12*k + 235711131719): alst.append(k)
return alst
print(aupto(500)) # Michael S. Branicky, May 12 2021
CROSSREFS
Sequence in context: A043413 A017041 A139692 * A047077 A326663 A086570
KEYWORD
base,nonn
AUTHOR
Parthasarathy Nambi, Mar 23 2005
EXTENSIONS
More terms from Stefan Steinerberger, Feb 15 2006
a(17) corrected by Daniel Starodubtsev, Jan 22 2020
STATUS
approved