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A105093 Numbers n such that n = prime(k) + prime(k+3) = prime(k+1) + prime(k+2) for some k. 4

%I #12 Mar 30 2020 18:15:46

%S 18,24,30,36,60,84,120,162,204,210,216,240,288,330,372,390,456,520,

%T 540,624,726,762,798,840,852,882,924,978,990,1104,1140,1164,1200,1392,

%U 1410,1428,1530,1632,1650,1716,1740,1764,1794,1848,1974,2052,2100,2112,2184

%N Numbers n such that n = prime(k) + prime(k+3) = prime(k+1) + prime(k+2) for some k.

%H Chai Wah Wu, <a href="/A105093/b105093.txt">Table of n, a(n) for n = 1..10000</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/GoldbachConjecture.html">Goldbach Conjecture</a>

%e a(1)=18 because prime(3)+prime(6)=prime(4)+prime(5)=5+13=7+11=18.

%t lst = {}; Do[ If[ Prime[n] + Prime[n + 3] == Prime[n + 1] + Prime[n + 2], AppendTo[lst, Prime[n] + Prime[n + 3]]], {n, 184}]; lst (* _Robert G. Wilson v_, Apr 07 2005 *)

%o (Python)

%o from sympy import nextprime

%o A105093_list, plist = [], [2,3,5,7]

%o while len(A105093_list) < 10000:

%o m = plist[0]+plist[3]

%o if m == plist[1]+plist[2]:

%o A105093_list.append(m)

%o plist = plist[1:] + [nextprime(plist[-1])] # _Chai Wah Wu_, Mar 30 2020

%Y Cf. A001172, A000954, first primes in A022885.

%K nonn

%O 1,1

%A _Giovanni Teofilatto_, Apr 06 2005

%E Edited and extended by _Robert G. Wilson v_, Apr 07 2005

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Last modified April 19 19:02 EDT 2024. Contains 371798 sequences. (Running on oeis4.)