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A000954 Conjecturally largest even integer which is an unordered sum of two primes in exactly n ways. 10

%I

%S 2,12,68,128,152,188,332,398,368,488,632,692,626,992,878,908,1112,998,

%T 1412,1202,1448,1718,1532,1604,1682,2048,2252,2078,2672,2642,2456,

%U 2936,2504,2588,2978,3092,3032,3218,3272,3296,3632,3548,3754,4022,4058,4412

%N Conjecturally largest even integer which is an unordered sum of two primes in exactly n ways.

%C The Goldbach conjecture is that every even number is the sum of two primes.

%H T. D. Noe, <a href="/A000954/b000954.txt">Table of n, a(n) for n = 0..5000</a>

%e 2 is largest even integer which is the sum of two primes in 0 ways, 12 is largest even integer which is the unordered sum of two primes in 1 way (5+7), etc.

%t f[n_] := Block[{c = 0, k = 3}, While[k <= n/2, If[PrimeQ[k] && PrimeQ[n - k], c++ ]; k++ ]; c]; a = Table[0, {50}]; a[[1]] = 2; a[[2]] = 4; Do[m = n; b = f[n]; If[b < 100, a[[b + 1]] = n], {n, 6, 20000, 2}] (* _Robert G. Wilson v_, Dec 20 2003 *)

%Y Cf. A045917, A023036, A000974, A001172, A002375.

%K nonn,nice

%O 0,1

%A _Bill Gosper_

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Last modified November 21 09:14 EST 2019. Contains 329362 sequences. (Running on oeis4.)