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 A178431 Joint-rank array of the sums of two primes. 2
 1, 2, 2, 4, 3, 4, 6, 5, 5, 6, 9, 7, 7, 7, 9, 11, 10, 8, 8, 10, 11, 14, 12, 12, 10, 12, 12, 14, 16, 15, 13, 13, 13, 13, 15, 16, 19, 17, 17, 15, 17, 15, 17, 17, 19, 23, 20, 18, 18, 18, 18, 18, 18, 20, 23, 25, 24, 21, 20, 21, 20, 21, 20, 21, 24, 25 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Joint-rank arrays are defined at A157927 for arrays in which duplicates occur (and otherwise, at A182801). LINKS EXAMPLE A corner of the array A178400 of sums of two primes: 4...5...7...9..13... 5...6...8..10..14... 7...8..10..12..14... 9..10..12..14..18... Each of these P(i,j) is replaced by its rank when all the numbers P(h,k) are jointly ranked, leaving A178431: 1...2...4...6...9... 2...3...5...7..10... 4...5...7...8..12... 6...7...8..10..13... The number of distinct sums p+q <=13 is 9. CROSSREFS Cf. A014092, A157927, A178400. Sequence in context: A079707 A233511 A205793 * A233574 A157927 A227256 Adjacent sequences:  A178428 A178429 A178430 * A178432 A178433 A178434 KEYWORD nonn,tabl AUTHOR Clark Kimberling, Dec 21 2010 STATUS approved

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Last modified September 25 18:51 EDT 2021. Contains 347659 sequences. (Running on oeis4.)