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A198438
Common differences in triples of squares in arithmetic progression, that are not a multiples of other triples in (A198384, A198385, A198386).
6
24, 120, 240, 336, 840, 840, 720, 1320, 2520, 2016, 3696, 2184, 5280, 5544, 6240, 3960, 3360, 9360, 10920, 10296, 4896, 6864, 14280, 18480, 6840, 22440, 17160, 10920, 20064, 28560, 9240, 31824, 31920, 31416, 26520, 16320, 12144, 41496, 47880, 43680, 50160
OFFSET
1,1
FORMULA
a(n) = A198387(A198409(n)) = A198436(n) - A198435(n) = A198437(n) - A198436(n).
MATHEMATICA
wmax = 1000;
triples[w_] := Reap[Module[{u, v}, For[u = 1, u < w, u++, If[IntegerQ[v = Sqrt[(u^2 + w^2)/2]], Sow[{u^2, v^2, w^2}]]]]][[2]];
tt = Flatten[DeleteCases[triples /@ Range[wmax], {}], 2];
#[[2]] - #[[1]]& /@ DeleteCases[tt, t_List /; GCD@@t > 1 && MemberQ[tt, t/GCD@@t]] (* Jean-François Alcover, Oct 22 2021 *)
PROG
(Haskell)
a198438 n = a198438_list !! (n-1)
a198438_list = map a198387 a198409_list
CROSSREFS
Sequence in context: A293893 A137799 A369541 * A256629 A114200 A229567
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Oct 25 2011
STATUS
approved