A104914 Numbers n such that the string 987654321k is prime.

1, 7, 37, 67, 77, 91, 109, 113, 133, 193, 197, 223, 317, 319, 331, 347, 371, 397, 403, 449, 491, 529, 569, 571, 587, 611, 623, 649, 673, 737, 743, 757, 767, 769, 851, 883, 893, 917, 919, 931, 989, 991, 1001, 1019, 1021, 1033, 1081, 1091, 1121, 1127, 1141

Offset

1,2

Links

Michael De Vlieger, Table of n, a(n) for n = 1..10000

Mathematica

With[{r = Reverse@ Range@ 9}, Select[Range[1200], PrimeQ[FromDigits[r ~Join~ IntegerDigits@ #]] &]] (* Michael De Vlieger, Jan 20 2018 *)
Select[Range[1200], PrimeQ[987654321*10^IntegerLength[#]+#]&] (* Harvey P. Dale, Jul 31 2018 *)

Prog

(Magma) [ n: n in [1..1750] | IsPrime(Seqint(Intseq(n) cat [1, 2, 3, 4, 5, 6, 7, 8, 9])) ]; // Vincenzo Librandi, Feb 02 2011

Crossrefs

Cf. A104915.

Sequence in context: A336494 A361485 A086110 * A032588 A123084 A123085

Adjacent sequences: A104911 A104912 A104913 * A104915 A104916 A104917

Keyword

nonn,base

Author

Zak Seidov, Mar 29 2005

Status

approved