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Zero, together with positive numbers k such that prime(k) + k is a square.
8

%I #26 Apr 13 2024 15:24:39

%S 0,5,12,86,105,176,214,230,241,412,503,696,1065,1147,1170,1273,1334,

%T 2021,2455,2600,2660,2772,3299,3332,3365,4417,4861,6478,6572,8115,

%U 8858,8905,9229,9380,9590,9692,9749,10501,10829,11338,11633,11690,12099

%N Zero, together with positive numbers k such that prime(k) + k is a square.

%H Harry J. Smith, <a href="/A064371/b064371.txt">Table of n, a(n) for n = 1..300</a>

%t Join[{0},Transpose[Select[Table[{n,Prime[n]},{n,15000}], IntegerQ[ Sqrt[ Total[#]]]&]][[1]]] (* _Harvey P. Dale_, May 26 2011 *)

%o (PARI) j=[]; for(n=0,20000, if(n==0 || issquare(prime(n)+n), j=concat(j,n))); j

%o (PARI) { n=0; default(primelimit, 20000000); for (m=0, 10^9, if (m==0 || issquare(prime(m) + m), write("b064371.txt", n++, " ", m); if (n==300, break)) ) } \\ _Harry J. Smith_, Sep 14 2009

%o (Magma) [0] cat [n: n in [1..12500] | IsSquare(NthPrime(n)+n)]; // _Bruno Berselli_, May 26 2011

%Y Cf. A014688.

%K nonn

%O 1,2

%A _Jason Earls_, Sep 26 2001

%E Edited by _Harry J. Smith_, Sep 14 2009