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A241488 Primes p such that p+8, p+888 and p+8888 are also prime. 1
53, 263, 389, 431, 983, 1013, 1061, 1223, 1571, 1823, 2789, 3323, 3533, 3911, 4211, 5849, 6563, 6653, 7019, 7481, 8369, 8963, 9041, 9173, 9413, 9539, 9803, 10091, 10559, 10979, 12611, 12689, 12911, 13163, 13751, 13781, 14243, 14879, 15083, 16691, 17231, 17483 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

All the terms in the sequence are congruent to 2 mod 3.

The constants in the definition (8, 888 and 8888) are the concatenation of digit 8.

LINKS

K. D. Bajpai, Table of n, a(n) for n = 1..10000

EXAMPLE

a(1) = 53 is a prime: 53+8 = 61, 53+888 = 941 and 53+8888 = 8941 are also prime.

a(2) = 263 is a prime: 263+8 = 271, 263+888 = 1151 and 263+8888 = 9151 are also prime.

MAPLE

KD:= proc() local a, b, d, e; a:= ithprime(n); b:=a+8; d:=a+888; e:=a+8888; if isprime(b)and isprime(d)and isprime(e)  then return (a) :fi; end: seq(KD(), n=1..5000);

MATHEMATICA

KD = {}; Do[p = Prime[n]; If[PrimeQ[p + 8] && PrimeQ[p + 888] && PrimeQ[p + 8888], AppendTo[KD, p]], {n, 5000}]; KD

(*For the b-file*)  c = 0; p = Prime[n]; Do[If[PrimeQ[p + 8] && PrimeQ[p + 888] && PrimeQ[p + 8888], c = c + 1; Print[c, "  ", p]], {n, 1, 5*10^6}];

Select[Prime[Range[2500]], AllTrue[#+{8, 888, 8888}, PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Jul 31 2017 *)

PROG

(PARI) s=[]; forprime(p=2, 18000, if(isprime(p+8) && isprime(p+888) && isprime(p+8888), s=concat(s, p))); s \\ Colin Barker, Apr 25 2014

CROSSREFS

Cf. A000040, A023200, A046136, A230223, A236302, A236304, A237890, A241485.

Sequence in context: A142061 A107150 A036911 * A140851 A253119 A253112

Adjacent sequences:  A241485 A241486 A241487 * A241489 A241490 A241491

KEYWORD

nonn

AUTHOR

K. D. Bajpai, Apr 23 2014

STATUS

approved

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Last modified August 18 20:02 EDT 2019. Contains 326109 sequences. (Running on oeis4.)