A204938 Irregular table T(n,k) of primes such that all terms in row n have a prime companion that sums to 10^n.

3, 5, 7, 3, 11, 17, 29, 41, 47, 53, 59, 71, 83, 89, 97, 3, 17, 23, 29, 47, 53, 59, 71, 89, 113, 137, 173, 179, 191, 227, 239, 257, 281, 317, 347, 353, 359, 383, 401, 431, 443, 479, 491, 509, 521, 557, 569, 599, 617, 641, 647, 653, 683, 719, 743, 761, 773

Offset

1,1

Comments

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.

Links

T. D. Noe, Rows n = 1..5, flattened

Example

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

Mathematica

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

Crossrefs

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

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

Sequence in context: A130141 A130142 A130139 * A101088 A134487 A064537

Adjacent sequences: A204935 A204936 A204937 * A204939 A204940 A204941

Keyword

nonn,tabf

Author

Livio Rosai, Jan 27 2012

Status

approved