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A167721 Squares that become prime numbers when prefixed with a 6. 1

%I #13 Jun 22 2016 08:27:51

%S 1,121,361,529,841,961,1681,2401,4489,5929,6889,8281,11449,16129,

%T 17161,17689,24649,28561,29929,32041,34969,39601,43681,48841,57121,

%U 61009,63001,64009,67081,73441,85849,96721,100489,116281,117649,124609,137641

%N Squares that become prime numbers when prefixed with a 6.

%C Subsequence of squares of A032669. - _Michel Marcus_, Jun 22 2016

%H G. C. Greubel, <a href="/A167721/b167721.txt">Table of n, a(n) for n = 1..10000</a>

%t Select[Range[500]^2,PrimeQ[6 10^IntegerLength[#]+#]&] (* _Harvey P. Dale_, May 11 2011 *)

%Y Cf. A032669.

%K base,nonn

%O 1,2

%A _Claudio Meller_, Nov 10 2009

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Last modified July 16 05:19 EDT 2024. Contains 374343 sequences. (Running on oeis4.)