A103753 - OEIS

A103753

Numbers k such that the string 235711k is prime.

9, 27, 39, 43, 73, 79, 109, 117, 129, 187, 213, 219, 241, 243, 247, 253, 297, 319, 327, 331, 361, 367, 369, 387, 417, 433, 447, 457, 471, 493, 513, 523, 537, 547, 577, 591, 601, 621, 633, 639, 643, 661, 699, 703, 709, 717, 727, 757, 759

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OFFSET

1,1

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

EXAMPLE

k=9 is in the sequence because 235711k = 2357119 is a prime number.

k=79 is in the sequence because 235711k = 23571179 is a prime number.

k=187 is in the sequence because 235711k = 235711187 is a prime number.

MATHEMATICA

Select[Range[800], PrimeQ[235711*10^IntegerLength[#]+#]&] (* Harvey P. Dale, Jul 20 2024 *)

PROG

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

CROSSREFS

Cf. A103630, A103629, A103590, A103540, A099192.

Sequence in context: A325299 A353238 A116455 * A238333 A103965 A069069

Adjacent sequences: A103750 A103751 A103752 * A103754 A103755 A103756

KEYWORD

base,nonn

AUTHOR

Parthasarathy Nambi, Mar 28 2005

STATUS

approved