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Numbers n with property that n^2 is a sum of some 120 successive primes.
1

%I #7 Jul 17 2019 13:59:23

%S 3734,3846,8660,10602,13248,13690,14318,14936,17934,20458,23902,27614,

%T 27704,29176,30942,31064,34238,35070,36216,38346,38532,38774,42236,

%U 42428,43190,43742,43794,47308,47622,49708,56070,57036,58856,65692,66122,66940,68016

%N Numbers n with property that n^2 is a sum of some 120 successive primes.

%C n^2=sum(prime(k),k=m,m+119); corresponding values of m: 10917, 11527, 50923, 73894, 111468, 118436, 128662, 139123, 195234 (A166261).

%e a(1)=3734: 3734^2=sum[Prime[i], {i,10917,10917+119}],

%e a(2)=3846: 3846^2=sum[Prime[i], {i,11527,11527+119}].

%t Select[Sqrt[#]&/@(Total/@Partition[Prime[Range[5*10^6]],120,1]),IntegerQ] (* _Harvey P. Dale_, Jul 17 2019 *)

%o (PARI) lista(nn) = {pr = primes(nn); for (i=1, nn-119, s = sum(k=i, i+119, pr[k]); if (issquare(s), print1(sqrtint(s), ", ")););} \\ _Michel Marcus_, Oct 15 2013

%Y Cf. A166261.

%K nonn

%O 1,1

%A _Zak Seidov_, Oct 10 2009

%E a(35)-a(37) from _Michel Marcus_, Oct 15 2013