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A194359
Triangle of divisors of 210^n, each number occurring once.
2
1, 2, 3, 5, 6, 7, 10, 14, 15, 21, 30, 35, 42, 70, 105, 210, 4, 9, 12, 18, 20, 25, 28, 36, 45, 49, 50, 60, 63, 75, 84, 90, 98, 100, 126, 140, 147, 150, 175, 180, 196, 225, 245, 252, 294, 300, 315, 350, 420, 441, 450, 490, 525, 588, 630, 700, 735, 882, 900
OFFSET
0,2
COMMENTS
The length of row k is A005917, the rhombic dodecahedral numbers, (k+1)^4 - k^4. The triangle has rows beginning with 2^k and ending with 210^k.
LINKS
T. D. Noe, Rows n = 0..9
MATHEMATICA
Join[{{1}}, Table[Complement[Divisors[210^n], Divisors[210^(n-1)]], {n, 9}]]
Take[DeleteDuplicates[Flatten[Divisors/@(210^Range[5])]], 100] (* Harvey P. Dale, Sep 03 2020 *)
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
T. D. Noe, Aug 26 2011
STATUS
approved