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A178400 Sums of two primes, an array by antidiagonals. 1
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 (list; table; graph; refs; listen; history; text; internal format)
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: A248926 A107575 A205677 * A114458 A205842 A061508

Adjacent sequences:  A178397 A178398 A178399 * A178401 A178402 A178403

KEYWORD

nonn,tabl

AUTHOR

Clark Kimberling, Dec 21 2010

STATUS

approved

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Last modified March 24 01:20 EDT 2019. Contains 321444 sequences. (Running on oeis4.)