A178400 Sums of two primes, an array by antidiagonals.

4, 5, 5, 6, 7, 7, 8, 8, 9, 9, 10, 10, 10, 12, 12, 13, 13, 14, 14, 14, 15, 15, 16, 16, 16, 16, 18, 18, 18, 18, 19, 19, 20, 20, 20, 20, 21, 21, 22, 22, 22, 22, 22, 24, 24, 24, 24, 24, 24, 25, 25, 26, 26, 26, 26, 26, 28, 28, 28, 28, 30, 30, 30, 30, 30, 30, 31

Offset

1,1

Comments

The joint-rank array of this array is A178431.

Links

Table of n, a(n) for n=1..67.

Formula

T(i,j)=p(i)+p(j), where p=(2,3,5,7,...)=A000040.

Example

Northwest corner:
4....5....7....9...13...
5....6....8...10...12...
7....8...10...12...16...
9...10...12...14...14...
T(1,1)=2+2=4.

Crossrefs

Cf. A000040, A014092.

Sequence in context: A107575 A350361 A205677 * A114458 A205842 A061508

Adjacent sequences: A178397 A178398 A178399 * A178401 A178402 A178403

Keyword

nonn,tabl

Author

Clark Kimberling, Dec 21 2010

Status

approved