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A248649
Numbers n that are the product of three distinct primes such that x^2+y^2 = n has integer solutions.
3
130, 170, 290, 370, 410, 442, 530, 610, 730, 754, 890, 962, 970, 986, 1010, 1066, 1090, 1105, 1130, 1258, 1370, 1378, 1394, 1490, 1570, 1586, 1730, 1802, 1810, 1885, 1898, 1930, 1970, 2074, 2146, 2290, 2314, 2330, 2378, 2405, 2410, 2465, 2482, 2522, 2570
OFFSET
1,1
COMMENTS
Union of 2*A131574 and A264498. - Ray Chandler, Dec 09 2019
LINKS
EXAMPLE
130 is in the sequence because 130 = 2*5*13, and x^2+y^2=130 has integer solutions (x,y) = (3,11) and (7,9).
1105 is in the sequence because x^2 + y^2 = 1105 = 5*13*17 has solutions (x,y) = (4,33), (9,32), (12,31) and (23,24).
MATHEMATICA
Select[Range[3000], PrimeNu[#]==PrimeOmega[#]==3&&FindInstance[x^2+y^2==#, {x, y}, Integers]!={}&] (* Harvey P. Dale, Dec 16 2023 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Colin Barker, Oct 12 2014
STATUS
approved