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A330174
Number of primitive Pythagorean triangles with sum of legs n.
3
0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 2
OFFSET
1,119
LINKS
MATHEMATICA
f[n_]:=Block[{ps, sps}, ps=First/@FactorInteger[n];
sps=Select[ps, MemberQ[{1, 7}, Mod[#, 8]]&];
If[sps==ps&&n!=1, 2^(Length[ps]-1), 0]]; Table[f[n], {n, 120}]
CROSSREFS
Sequence in context: A285936 A322358 A322437 * A336835 A353418 A361161
KEYWORD
nonn
AUTHOR
Ray Chandler, Feb 15 2020
STATUS
approved