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Irregular table T(n,k) of primes such that all terms in row n have a prime companion that sums to 10^n.
1

%I #24 Aug 03 2014 14:01:37

%S 3,5,7,3,11,17,29,41,47,53,59,71,83,89,97,3,17,23,29,47,53,59,71,89,

%T 113,137,173,179,191,227,239,257,281,317,347,353,359,383,401,431,443,

%U 479,491,509,521,557,569,599,617,641,647,653,683,719,743,761,773

%N Irregular table T(n,k) of primes such that all terms in row n have a prime companion that sums to 10^n.

%C Row 1 has 3 terms. Row 2 has 12 terms. Row 3 has 56 terms. All rows after the first have an even number of terms.

%H T. D. Noe, <a href="/A204938/b204938.txt">Rows n = 1..5, flattened</a>

%e 3+7=10, 41+59=100, 317+683=1000.

%t Flatten[Table[ps = Prime[Range[PrimePi[10^n]]]; Select[ps, MemberQ[ps, 10^n - #] &], {n, 3}]] (* _T. D. Noe_, Jan 27 2012 *)

%Y Cf. A107318 (number of terms in row n).

%Y Cf. A126691, A126692, A126693 (primes that sum to 100, 1000, and 10000).

%K nonn,tabf

%O 1,1

%A _Livio Rosai_, Jan 27 2012