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A232766 Numbers n such that the concatenation n987654321 is prime. 2
28, 32, 44, 50, 55, 58, 97, 100, 107, 112, 130, 149, 152, 154, 179, 193, 208, 233, 259, 265, 271, 287, 310, 314, 320, 326, 341, 359, 365, 376, 404, 413, 421, 439, 449, 455, 457, 466, 469, 491, 499, 536, 538, 545, 547, 548, 557, 565, 568, 574, 593, 614, 616 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..53.

EXAMPLE

314 is a member of this sequence because 314987654321 is prime.

PROG

(Python)

from sympy import isprime

{print(n, end=', ') for n in range(2000) if isprime(int(str(n)+"987654321"))}

# Simplified by Derek Orr, Apr 10 2015

(PARI) for(n=1, 2000, if(isprime(eval(concat(Str(n), "987654321"))), print1(n, ", "))) \\ Derek Orr, Apr 10 2015

(MAGMA) [n: n in [0..1000] | IsPrime(Seqint(Intseq(987654321) cat Intseq(n)))]; // Vincenzo Librandi, Apr 11 2015

CROSSREFS

Cf. A232767, A104914, A104915.

Sequence in context: A025367 A121018 A232727 * A230855 A090637 A261113

Adjacent sequences:  A232763 A232764 A232765 * A232767 A232768 A232769

KEYWORD

nonn,base

AUTHOR

Derek Orr, Nov 29 2013

EXTENSIONS

More terms from Derek Orr, Apr 10 2015

STATUS

approved

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Last modified March 26 00:37 EDT 2019. Contains 321479 sequences. (Running on oeis4.)