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 A068701 Primes in the concatenation n^2, n and 1. 2

%I #10 Sep 08 2022 08:45:05

%S 421,2551,6481,8191,289171,729271,1024321,1521391,1681411,3136561,

%T 3600601,4225651,4356661,4624681,5184721,6084781,7921891,9604981,

%U 116641081,136891171,144001201,163841281,174241321

%N Primes in the concatenation n^2, n and 1.

%H Vincenzo Librandi, <a href="/A068701/b068701.txt">Table of n, a(n) for n = 1..1000</a>

%e 6481 is a prime which is a concatenation of 8^2, 8 and 1.

%t Select[Table[FromDigits[Flatten[{IntegerDigits[n^2], IntegerDigits[n], {1}}]], {n, 1000}], PrimeQ] (* _Vincenzo Librandi_, Mar 13 2013 *)

%o (Magma) [nn1: n in [1..200] | IsPrime(nn1) where nn1 is Seqint([1] cat Intseq(n) cat Intseq(n^2))]; // _Vincenzo Librandi_, Mar 13 2013

%K base,nonn

%O 1,1

%A _Amarnath Murthy_, Mar 04 2002

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Last modified September 11 23:02 EDT 2024. Contains 375842 sequences. (Running on oeis4.)