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A228761 Primes of the concatenated form 149x149 for some number x. 1

%I #17 Jan 14 2015 17:59:58

%S 1496149,1497149,1499149,14915149,14924149,14925149,14928149,14931149,

%T 14942149,14945149,14951149,14976149,14985149,14991149,149124149,

%U 149127149,149132149,149135149,149150149,149153149,149159149,149162149,149171149,149175149,149187149,149192149

%N Primes of the concatenated form 149x149 for some number x.

%C Sequence is infinite. - _Charles R Greathouse IV_, Sep 03 2013

%H K. D. Bajpai, <a href="/A228761/b228761.txt">Table of n, a(n) for n = 1..2000</a>

%F Primes of the form parse(cat(149,x,149)).

%e a(1)= 1496149 is a term in the sequence as it is a prime of the form abcxabc: abc are square digits 1,4 and 9 in order.

%p with(StringTools): KD:= proc() local a,b; a:= 149; b:=parse(cat(a,x,a)); if isprime(b) then RETURN(b): fi; end: seq(KD(),x=1..1000);

%t With[{c={1,4,9}},Select[Table[FromDigits[Join[c,IntegerDigits[n],c]],{n,200}],PrimeQ]](* _Harvey P. Dale_, Jan 14 2015 *)

%o (PARI) for(x=1,1e3,if(ispseudoprime(t=eval(Str(149,x,149))), print1(t", "))) \\ _Charles R Greathouse IV_, Sep 03 2013

%K nonn,base,less

%O 1,1

%A _K. D. Bajpai_, Sep 03 2013

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Last modified July 13 17:55 EDT 2024. Contains 374285 sequences. (Running on oeis4.)