A099192 Numbers k such that the string k235711131719 is prime.

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

Daniel Starodubtsev, Table of n, a(n) for n = 1..10000

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

Adjacent sequences: A099189 A099190 A099191 * A099193 A099194 A099195

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