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A179612
Sums of pairs of betrothed (or quasi-amicable) numbers.
1
123, 335, 2975, 3223, 4319, 11903, 25479, 30239, 138239, 393119, 416639, 508895, 773759, 861839, 1071359, 1391039, 1645055, 2903039, 2413151, 2298239, 2903039, 2515199, 2557439, 2757887, 2695679, 3856895, 4147199, 4717439, 4245695, 4561919, 5391359, 5322239
OFFSET
1,1
COMMENTS
This is to A161005 sums of pairs of amicable numbers as betrothed (or quasi-amicable) numbers A005276 are to A063990 amicable numbers. The subsequence of primes begins: 11903, 138239, 1071359.
FORMULA
a(n) = A003502(n) + A003503(n). {(j + k) such that sigma(j)=sigma(k)=j+k+1, where sigma=A000203}.
EXAMPLE
a(1) = 48 + 75 = 123 = 3 * 41.
a(2) = 140 + 195 = 335 = 5 * 67.
a(6) = 5775 + 6128 = 11903 is the smallest prime in these pair-sums.
CROSSREFS
KEYWORD
nonn
AUTHOR
Jonathan Vos Post, Jan 08 2011
EXTENSIONS
More terms from Amiram Eldar, Jan 27 2019
STATUS
approved