A139327 -id:A139327 - cp's OEIS frontend

A139325 Triangle read by rows: T(n,k) = number of primes in the k-th row of the square of the first n^2 odd numbers written consecutively in rows of length n, 1<=k<=n.

0, 1, 2, 2, 2, 2, 3, 2, 3, 2, 3, 4, 2, 2, 3, 4, 4, 2, 4, 2, 3, 5, 3, 4, 3, 3, 4, 2, 5, 5, 4, 3, 4, 2, 5, 2, 6, 4, 5, 4, 4, 4, 2, 4, 3, 7, 4, 5, 5, 3, 5, 4, 3, 4, 5, 7, 6, 4, 5, 6, 3, 4, 4, 5, 2, 6, 8, 6, 5, 4, 6, 4, 5, 4, 4, 5, 4, 5, 8, 6, 6, 6, 4, 5, 6, 4, 5, 4, 6, 3, 4, 8, 7, 7, 6, 5, 5, 5, 4, 6, 5, 4, 4, 5, 5

Offset: 1

Reinhard Zumkeller, Apr 14 2008

A139326(n) = Min{T(n,k): 1<=k<=n};
A139327(n) = Max{T(n,k): 1<=k<=n};
A139328(n) gives sums of rows;
T(n,1) = A099802(n) - 1.

Cf. A083415.

A139326 Write the first n^2 odd numbers consecutively in n rows of length n: a(n) = minimal number of primes in a row.

Original entry on oeis.org

0, 1, 2, 2, 2, 2, 2, 2, 2, 3, 2, 4, 3, 4, 4, 4, 3, 3, 4, 5, 4, 6, 5, 5, 5, 5, 5, 5, 4, 5, 5, 5, 6, 6, 5, 5, 5, 8, 6, 7, 7, 8, 7, 7, 8, 8, 8, 9, 9, 8, 9, 9, 10, 10, 9, 9, 8, 9, 9, 9, 10, 10, 11, 9, 11, 10, 11, 10, 11, 11, 11, 12, 12, 12, 13, 12, 13, 13, 13, 12, 13, 14, 15, 14, 12, 13, 13, 15, 14

Offset: 1

Reinhard Zumkeller, Apr 14 2008

nonn

a(n) = Min{A139325(n,k): 1<=k<=n}.

			a(4)=Min{#{3,5,7},#{11,13},#{17,19,23},#{29,31}}=Min{3,2,3,2}=2:
..1 ...3 ...5 ...7 ... primes in first row = {3,5,7},
..9 ..11 ..13 ..15 ... primes in 2nd row = {11,13},
.17 ..19 ..21 ..23 ... primes in 3rd row = {17,19},
.25 ..27 ..29 ..31 ... primes in 4th row = {29,31}.

Cf. A139327, A083382.

cp's OEIS Frontend

A139325 Triangle read by rows: T(n,k) = number of primes in the k-th row of the square of the first n^2 odd numbers written consecutively in rows of length n, 1<=k<=n.

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