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A213739 Numbers n such that n and n^2 are sums of two successive primes. 2

%I #15 Aug 11 2014 22:45:48

%S 12,24,42,84,90,120,204,240,372,410,456,600,630,740,762,852,882,978,

%T 1088,1140,1148,1272,1460,1518,1584,1620,1656,1758,1770,1878,1900,

%U 1960,2052,2316,2562,2688,2886,2992,3570,3634,3678,3738,3750,3924,4170,4314,4906

%N Numbers n such that n and n^2 are sums of two successive primes.

%C First terms not multiple of 6: 410, 740, 1088, 1148, 1460, 1900, 1960.

%H Charles R Greathouse IV, <a href="/A213739/b213739.txt">Table of n, a(n) for n = 1..10000</a>

%H Zak Seidov, <a href="/A213739/a213739.txt">Table of n,p,q,n^2,r,s</a>

%e 12=5+7, 144=71+73;

%e 24=11+13, 576=283+293;

%e 42=19+23, 1764=881+883.

%t Reap[ Do[ If[ (p=NextPrime[n/2, -1]; p+NextPrime[p] == n) && (q=NextPrime[n^2/2, -1]; q+NextPrime[q] == n^2) , Sow[n]], {n, 2, 5000, 2}]][[2, 1]] (* _Jean-François Alcover_, Jul 17 2012 *)

%o (PARI) p=2;forprime(q=3,1e3,n=p+q;if(precprime(n^2/2)+nextprime((n^2+1)/2)==n^2,print1(n", "));p=q) \\ _Charles R Greathouse IV_, Jun 21 2012

%Y Intersection of A001043 and A074924.

%K nonn

%O 1,1

%A _Zak Seidov_, Jun 19 2012

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Last modified April 23 16:40 EDT 2024. Contains 371916 sequences. (Running on oeis4.)